How does FreeSWITCH compare to Asterisk? The Back Story of Free Switch IP-PBX

Source: http://www.freeswitch.org/node/117

Author / Founder: Free Switch

Note: CudaTel a IP-PBX from Barracuda ( http://www.BarraGuard.com )

Visit: Virtual Graffiti for your Technology and Network Security Needs!  http://www.VirtualGraffiti.com

How does FreeSWITCH compare to Asterisk? Why did you start over with a new application? These are questions I’ve been hearing a lot lately so I decided to explain it for all of the telephony professionals and enthusiasts alike who are interested to know how the two applications compare and contrast to each other. I have a vast amount of experience with both applications with about 3 years of doing asterisk development under my belt and well, being the author of FreeSWITCH. First I will provide a little history and my experience with Asterisk, then I will try to explain the motivations and the different approach I took with FreeSWITCH.

I first tried Asterisk in 2003. It was still pre 1.0 and VoIP was still very new to me. I downloaded and installed it and in a few minutes I was tickled pink over the dial tone emitting from my phone plugged into the back of my computer. I spent the next few days playing with my dial plan and racking my brain to think of cool stuff I could do with a phone that was hooked up to a Linux PC. Since I had done an extensive amount of web development in my past life I had all sorts of nifty ideas like matching the caller id to the customer’s account number and trying to guess why they were calling etc. I also wanted to move on in my dial plan based on pattern matching and started hacking my first module. Before I knew it I had made the first cut of app_perl, now res_perl where I had embedded a Perl5 interpreter in Asterisk.

Now that I had that out of my system, I started developing an Asterisk-driven infrastructure to use for our inbound call Queues. I prototyped it using app_queue and the Manager Interface now proudly dubbed “AMI” (initials always make things sound cooler). It was indeed magnificent! You could call in from a PSTN number over a T1 and join a call queue where our agents who also called in could service the calls. “This rocks!” I thought to myself as I watched from my fancy web page showing all the queues and who was logged in. It even refreshed periodically by itself which was why I was surprised when the little icon in the corner of my browser was still spinning for quite some time. That’s when I first heard it. That word. The one I can never forget, deadlock.

That was the first time, but it wasn’t the last. I learned all about the GNU debugger that day and it was just the first of many incidents. Deadlock in the queue app. Deadlock in the manager, Avoiding Deadlock on my console. It was starting to get to me a little but I kept going. By this time I was also quite familiar with the term Segmentation Fault another foe to the computer developer. After about a year’s time wrestling with bugs I found myself a lot more well-versed in the C programming language than I even imagined and near Jedi caliber debugging skills. I had a working platform running several services on a DS3 worth of TDM channels spread over 7 asterisk boxes and I had given tons of code to the project including some entire files on which I hold the copyright. http://www.cluecon.com/anthm.html

By 2005, I had quite a reputation as an asterisk developer. They even thanked me in both the CREDITS file and in the book, Asterisk, The Future of Telephony. I not only had tons of applications for asterisk in tree, I had my own collection of code they did not need or want on my own site. (Still available today at http://www.freeswitch.org/node/50)
Despite all of this I could not completely escape the deadlocks and crashes. I hid the problem well with restart scripts and 7 machine clusters but I could not see a way to scale my platform much more. I had to abandon some features because they just would not work right based on the way Asterisk was designed.

Asterisk uses a modular design where a central core loads shared objects to extend the functionality with bits of code known as “modules”. Modules are used to implement specific protocols such as SIP, add applications such as custom IVRs and tie in other external interfaces such as the Manager Interface. The core of Asterisk is a threading model but a very conservative one. Only origination channels and channels executing an application have threads. The B leg of any call operate only within the same thread as the A leg and when something happens like a call transfer the channel must first be transferred to a threaded mode which often times includes a practice called channel masquerade, a process where all the internals of a channel are torn from one dynamic memory object and placed into another. A practice that was once described in the code comments as being “nasty”. The same went for the opposite operation the thread was discarded by cloning the channel and letting the original hang-up which also required hacking the cdr structure to avoid seeing it as a new call. One will often see 3 or 4 channels up for a single call during a call transfer because of this.

/* XXX This is a seriously wacked out operation. We’re essentially putting the guts of
the clone channel into the original channel. Start by killing off the original
channel’s backend. I’m not sure we’re going to keep this function, because
while the features are nice, the cost is very high in terms of pure nastiness. XXX */

This became the de facto way to pull a channel out of the grips of another thread and the source of many headaches for application developers. This uncertain threading scheme was one of the motivating factors for a rewrite.

Asterisk uses linked-lists to manage its open channels. A linked-list is a series of dynamic memory chained together by using a structure that has a pointer to its own type as one of the members allowing you to endlessly chain objects and keep track of them.
They are indeed a useful programming practice but when used in a threaded application become very difficult to manage. One must use mutexes, a kind of traffic light for threads to make sure only 1 thread ever has write access to the list or you risk one thread tearing a link out of a list while another is traversing it. This also leads to horrible situations where one thread may be destroying or masquerading a channel while another is accessing it which will result in a Segmentation Fault which is a fatal error in the program and causes it to instantly halt which, of course means in most cases all your calls will be lost. We’ve all seen the infamous “Avoiding initial deadlock” message which essentially is an attempt to lock a channel 10 times and if still won’t lock, just go ahead and forget about the lock.

The manager interface or AMI has a concept where the socket used to connect the client is passed down into the applications letting your module have direct access to it and essentially write any data you want to that socket in the form of Manager Events which are not very structured and thus the protocol is very difficult to parse.

Asterisk’s core has linking dependencies on some of it’s modules which means that the application will not start if a certain module is not present because the core is actually using some of the binary code from the module shared object directly. To make a call in asterisk in at least version 1.2 you have no choice but to use app_dial and res_features because the code actually lives in those modules. The logic to establish a call and to do things like a forked dial actually reside in app_dial not the core, and res_features actually contains the top level function that bridges the audio.

Asterisk has no protection of its API. The majority of the functions and data structures are public and can easily be misused or bypassed. The core is anarchy with assumptions about channels having a file descriptor, which is not always necessary in reality but is mandatory for any asterisk channel. Many algorithms are repeated throughout the code in completely different ways with every application doing something different on seemingly identical operations.

This is only a brief summary of the leading issues I had with Asterisk. I donated my time as a coder, my servers to host the CVS repository and served as a bug marshal and maintainer. I organized a weekly conference call to plan for the future and address some of the issues I have described above. The problem was, when one looks at this long list of fundamental changes then thinks about how much work it would take and how much code may have to be erased or rewritten, the motivation to address the issues begins to fade. I could tell not many people would be on board with my proposal to start a 2.0 branch and rewrite the code. That is why in the summer of 2005 I decided I would do it myself.

My primary focus on FreeSWITCH was to start from the core and trap all the common functionality under the hood and expose it in a pyramid to the higher levels of the application. Like Asterisk, the Apache Web Server heavily inspired me and I chose to use a modular design. From the first day the basic fundamentals I chose to adhere to were that every channel has it’s own thread no matter what it was doing and that thread would use a state machine function to navigate its way through the core. This would ensure that every channel would follow the same predictable path and state hooks and overrides could be placed into the machine to add important functionality very similar to how methods and class inheritance works in an object oriented programming language.

It hasn’t been easy. Let me tell you. I’ve had my fair share of Segmentation Faults and Deadlocks while coding FreeSWITCH , (a lot more of the former than the latter I must say). But I built the code from the core and went from there. Since all of the channels operate in their own thread and there are occasions where you need to interact with them, I use read/write locking so the channels can be located from a hashing algorithm rather than a linked list and there is an absolute guarantee that the channel cannot be accessed or go away while an outside thread has reference to it. This alone makes it much easier to sleep at night and obsoletes the need for “Channel Masquerades” and other such voodoo.

The majority of functions and objects supplied by the FreeSWITCH core are protected from the caller by forcing them to be used the way they were designed. Any concept that is extensible or provided by a module has a specific interface which is used to front end that functionality therefore the core has no linking dependency on any of its modules.
There is a clear cut layered API with the core functions being on the bottom and the amount of functions on each subsequent layer decreasing as the functionality increases.
For instance it’s possible to write a large function that uses an arbitrary file format module to open and play audio to a channel. But in the next layer of API there is simply a single function that will play a file to a channel that is then extended to the dial plan tools module as a tiny application interface function. So you can execute the playback from your dial plan, from your custom C application using the same function or you can write your own module that manually opens the file and plays it all using the services of the file format class of modules without ever divulging it’s code.

FreeSWITCH is broken into several module interfaces. Here is a list of them:

Dialplan:
Implement the ring state of a call, take the call data and make a routing decision.

Endpoint:
Protocol specific interface SIP, TDM etc.

ASR/TTS:
Speech recognition and synthesis.

Directory:
LDAP type database lookups.

Events:
Modules can fire existing core events as well as register their own custom events
Which can be parsed from an event consumer at a later time.

Event Handlers:
Remote access to events and CDR.

Formats:
File formats such as wav.

Loggers:
Console or file logging.

Languages:
Embedded languages such as Python and JavaScript.

Say:
Language specific modules to construct utterances from sound files.

Timers:
Reliable timers for packet interval timing.

Applications:
Applications you can execute on the call such as Voicemail.

FSAPI (FreeSWITCH API interface [see I use initials too!] )
Command line functions, XMLRPC functions, CGI type functions, Dialplan function variables exposed with a string in, string out prototype.

XML
There are hooks to the core XML registry that make it possible to do realtime
lookups and create XML based CDRs

All of the FreeSWITCH modules work together and communicate with each other only via the core API and the internal event system. Great care was taken to ensure this and avoid any unwanted behavior from outside modules.

The event system in FreeSWITCH was designed to keep track of as much as possible. I designed it under the assumption that most users of the software would be connecting to FreeSWITCH remotely or using a custom module to gather call data. Thus, every important thing that happens in FreeSWITCH results in an event firing. The events are very similar to an email format having headers and a body. Events can be serialized into either a standard text format or an XML representation. Any number of modules may be written to connect to the event subsystem and receive events about presence, call state and failures. The in-tree mod_event_socket provides a TCP connection on which events can be consumed as well as log data. In addition call control commands may be sent over this interface as well as bi-directional audio flow. The socket can be established by either an in-progress call as an outbound connection or from a remote machine as an inbound connection.

Another important concept in FreeSWITCH is the centralized XML registry. When FreeSWITCH loads it opens a top-level XML file which is fed into a pre-processor that parses special directives to include other smaller xml files and to set global variables which can be referenced from that point forward to template the configuration.
For instance you can set the preprocessor directive to set a global variable like this:

<X-PRE-PROCESS cmd=”set” data=”moh_uri=local_stream://moh”/>

now even on the next line in the file you can use $${moh_uri} and it will be replaced by local_stream://moh in the post processed output. The final post processed registry is loaded into memory and accessed by the modules and the core to provide several vital sections to the application:

Configuration
Configuration data to control the behaviour of the application.

Dialplan
An XML representation of a dialplan that can be used by mod_dialplan_xml to
route calls and execute applications.

Phrases
A markup of IVR phrase macros to use from IVRs and to speak multiple languages.

Directory
A collection of domains and users for registration and account management.

Using XML hook modules, you can bind your module to lookups in the XML registry and, in real time, gather the required information and return it to the caller in place of the static data in the file. This makes it possible to do purely dynamic SIP registrations and dynamic voice mailboxes and dynamic configuration of a cluster using the same model as a web browser and a CGI application.

With embedded languages such as JavaScript, Java, Python and Perl, it’s possible to write scripted application that can control the underlying power with a simple high-level interface.

The first phase of the FreeSWITCH project was to create a stable core on which to build scalable applications. I am happy to report that it will be completed on May 26th 2008 with the release of FreeSWITCH 1.0 “phoenix”. We have been able to out perform Asterisk by a factor of 10 in similar situations according to the accounts of two separate early adopters brave enough to go into production pre-1.0.

I hope this explanation is sufficient to outline the difference between FreeSWITCH and Asterisk and will shed some light on my decision to start the FreeSWITCH project. I will forever remain an Asterisk developer due to my vast involvement in the project and I wish them all the luck in the world with the future design of the application. I may even dig up some more of my long lost Asterisk code in my personal archives and release it to the public as a gesture of good will towards the project that gave me my start in telephony.

Asterisk is an open source PBX and FreeSWITCH is an open source soft switch. There is plenty of room for both applications among the other great open source Telephony applications such as Call Weaver, Bayonne, sipX, OpenSER and many many more. I look forward every year to presenting with and talking to all the developers of these projects at ClueCon in Chicago this summer. http://www.cluecon.com

We can all inspire each other to push the envelope on Telephony even farther. The most important question you can ask is. “Is it the right tool for the job?”

//

 

Network Notepad creates quick diagrams and flow charts

Filed under: Business, Utilities, Windows, Productivity, Freeware

 

by Lee Mathews Oct 31st 2008 at 10:00AM

While network planning and design isn’t usually part of my job, I do sometimes need to put together a quick sketch of a client’s systems to help me oragnize a plan of attack.

Network Notepad is exactly what I was looking for – a small, free app that lets me lay out network devices, servers, printers, and workstations quickly and easily. It’s a great tool for documenting sites in case another tech has to attend to a call in my absence. Once you’ve set IP addresses, you’re able to use the F1-F6 keys as hotkeys to ping, surf, or telnet to a device.

Don’t be fooled by the Notepad in the name, though. This app is full-featured enough to tackle complicated networks. Be sure to download the Cisco-created object libraries and hub/switch pack, as they provide several icons that aren’t included in the default set.

There’s even a flow chart icon pack which turns Notepad into a kind of poor man’s Visio (if you’re looking for a Visio clone, try the open source Dia). You can’t argue with the price, and the feature set is impressive for such a small download.

Tags: diagram, diagramming, flow chart, flowchart, networking

Technology Updates: 04/27/09

Safend, today announced a new release of Safend Encryptor, a hard-disk encryption solution that is a component of the Safend Data Protection Suite.

http://safend-security.blogspot.com/2009/04/safend-announces-safend-data-protection.html

 

VMware, Inc. today announced VMware vSphere™ 4

http://vmware-software.blogspot.com/2009/04/vmware-unveils-industrys-first.html

 

Check Point Software Technologies Ltd. today announced a new high-end Power-1 series of Power-1 11000

http://checkpoint-security.blogspot.com/2009/04/check-point-introduces-new-high-end.html

 

WatchGuard Technologies today unveiled its new operating system for WatchGuard security appliances – WatchGuard Fireware XTM

http://watchguard-guardsite.blogspot.com/2009/04/watchguard-sets-new-standard-for.html

 

eEye Digital Security today announced the general availability of Blink Server 4

http://eeye-security.blogspot.com/2009/04/new-eeye-blink-server-4-edition-to.html

 

ZyXEL Communications Inc , today announced a high-end addition to its already powerful line of Unified Threat Management (UTM) products, the ZyWALL USG2000.

http://zyxelguard.blogspot.com/2009/04/zyxel-introduces-high-end-unified.html

 

FaceTime Communications today introduced FaceTime Insight™,

http://facetime-security.blogspot.com/2009/04/facetime-introduces-powerful.html

 

Marshal8e6 has today announced the acquisition of Avinti

http://8e6-security.blogspot.com/2009/04/rss-feed-of-news-from-marshal8e6.html

 

Virtual Graffiti, Inc

http://www.VirtualGraffiti.com

 

ParagonHost

http://www.ParagonHost.com

All the week’s news and views about Security, 04/16/09

All the week’s news and views about Security, 04/16/09

Botnets: Reasons It’s Getting Harder to Find and Fight Them
http://www.networkworld.com/nlsecuritynewsal192072

 

The perpetual proliferation of botnets is hardly surprising when
one considers just how easy it is for the bad guys to hijack
computers without tipping off the users.Read full story
http://www.networkworld.com/nlsecuritynewsal192072

Senior Editor Ellen Messmer covers security for Network World.
E-mail Ellen mailto:emessmer@nww.com .

_______________________________________________________________
This newsletter is sponsored by Oracle
The Cost of Securing your Database

Make the most of IT security and compliance dollars by ensuring
your databases are secure. Get concrete tips and recommendations
in this Live Webcast sponsored by Oracle, scheduled for
Thursday, April 16, 2009 at 2:00 p.m. ET/11:00 a.m. PT. Learn
how to cost-effectively safeguard sensitive and regulated
information. Register for this Live Webcast now.
http://adserver.fattail.com/redir/redirect.asp?CID=296041
_______________________________________________________________
Responsible for building a resilient data center Then don’t miss
Network World’s one-day conference and expo devoted to best
practices and new solutions. Hear top analysts. Meet key vendors.
Coming to 10 cities in ‘09 including Boston in May and Atlanta in
June. Register now to attend free: Visit
http://www.nww.com/rpgx.jsp?c=XU1PTA1012Z4303.

_______________________________________________________________

 

RELATED EDITORIAL LINKS

Stealthy rootkit slides further under the radar
http://www.networkworld.com/nlsecuritynewsal192073  Thousands of
Web sites have been rigged to deliver a powerful piece of
malicious software that many security products may be unprepared
to handle.

Oracle delivers major security patch update
http://www.networkworld.com/nlsecuritynewsal192074  Oracle
released 43 security fixes on Tuesday for a range of
applications, including its flagship database, Oracle
Application Server, E-Business Suite, PeopleSoft Enterprise and
WebLogic Server.

UC security: When the shoe doesn’t fit – compress the foot
http://www.networkworld.com/nlsecuritynewsal192075  If your
security model is location-centric and depends on keeping things
separate, how do you respond to a disruptive technology like
unified communications? This is a pattern that keeps repeating
in many different areas: the security paradigm looked good until
a technology comes along, changes the assumptions and reveals
the inadequacy of the model.

CDT: Privacy, transparency needed in cybersecurity policy
http://www.networkworld.com/nlsecuritynewsal192076  U.S.
President Barack Obama’s administration and Congress will have
to address major civil liberties and transparency concerns as
they create new policies to tackle ongoing cybersecurity
vulnerabilties in the government and private industry, a digital
rights group said.

Human ear could be next biometric system
http://www.networkworld.com/nlsecuritynewsal192077  British
scientists are investigating the viability of a new biometric
technique that would make use of the human ear as a way for a
third party to identify the person they are speaking to.

Deleted Data Drives New Data Breaches
http://www.networkworld.com/nlsecuritynewsal192078  According to
a new report on data breaches from Verizon Business, cyber
criminals are no longer attacking where the credit card files
are, but where they once were.

Encrypt more data with latest SecuriKey version
http://www.networkworld.com/nlsecuritynewsal192079  When last we
heard from the folks at GT SecuriKey, the makers of the
hardware-software combo for securing laptops had just come out
with a bundle aimed at mobile Mac users who also ran Windows on
their portables via Boot Camp. Now the cross-platform data
security company is updating all of its Mac offerings, with
enhanced data encryption features in the latest version of
SecuriKey.

Top Trends: Patch Management
http://www.networkworld.com/nlsecuritynewsal185732  Find out how
patch-management products work, and what they can do for you, in
this Product Guide.

April giveaways http://www.networkworld.com/community/node/40434
galore
Cisco Subnet http://www.networkworld.com/subnets/cisco/
andMicrosoft Subnet
http://www.networkworld.com/subnets/microsoft/  are giving away
training courses from Global Knowledge, valued at $2,995 and
$3,495, and have copies of three hot books up for grabs:CCVP
CIPT2 Quick Referenceby Anthony Sequeira,Microsoft Voice Unified
Communicationsby Joe Schurman andMicrosoft Office 2007 On
Demandby Steve Johnson.Deadline for entries
http://www.networkworld.com/community/node/40434  April 30.

Network World on Twitter  http://twitter.com/NetworkWorld  Get
our tweets and stay plugged in to networking news.
TOP STORIES | MOST DUGG STORIES
       http://www.networkworld.com/nlsecuritynewsal192080

1. NASA takes Ethernet deeper into space
       http://www.networkworld.com/nlsecuritynewsal192081

2. EBay to spin off Skype by mid-2010
       http://www.networkworld.com/nlsecuritynewsal192082

3. Microsoft’s Patch Tuesday filled with zero-day exploits
       http://www.networkworld.com/nlsecuritynewsal192083

4. Fact-checking the fact-checkers: Snopes.com gets an ‘A’
       http://www.networkworld.com/nlsecuritynewsal192084

5. Managing IP addresses with free tools
       http://www.networkworld.com/nlsecuritynewsal192085

6. Exchange 2010: Sneak peek
       http://www.networkworld.com/nlsecuritynewsal192086

7. Breakthrough enables Terabit Ethernet
       http://www.networkworld.com/nlsecuritynewsal192087

8. 15 nifty BlackBerry apps for IT pros
       http://www.networkworld.com/nlsecuritynewsal192088

9. Exchange 2010 beta leads kickoff of new Office lineup
       http://www.networkworld.com/nlsecuritynewsal192089

10. Recession resistant: 10 technologies CIOs are still buying
       http://www.networkworld.com/nlsecuritynewsal192090

       http://twitter.com/NetworkWorld

MOST-WATCHED VIDEO1. Students learn through robot battles
       http://www.networkworld.com/nlsecuritynewsal192091
_______________________________________________________________
This newsletter is sponsored by Oracle
The Cost of Securing your Database

Make the most of IT security and compliance dollars by ensuring
your databases are secure. Get concrete tips and recommendations
in this Live Webcast sponsored by Oracle, scheduled for
Thursday, April 16, 2009 at 2:00 p.m. ET/11:00 a.m. PT. Learn
how to cost-effectively safeguard sensitive and regulated
information. Register for this Live Webcast now.
http://adserver.fattail.com/redir/redirect.asp?CID=296041
_______________________________________________________________

Technology Update: 03-30-09

Kaspersky Lab announces the launch of Kaspersky Internet Security 2009 for Ultra-Portables.

http://kasperskyav.blogspot.com/2009/03/kaspersky-lab-launches-comprehensive.html

 

Cymphonix announced Network Revealer

http://cymphonix.blogspot.com/2009/03/cymphonix-provides-free-tool-to-help-it.html

 

Cisco Announces Intent to Acquire Pure Digital Technologies, Makers of Flip Video

http://linksys-works.blogspot.com/2009/03/cisco-announces-intent-to-acquire-pure.html

 

SonicWALL, Inc. , today announced the immediate availability of its new E-Class Email Security Appliance (ESA) ES8300

http://sonic-wall.blogspot.com/2009/03/innovative-email-security-protection.html

 

IT security and control firm Sophos is warning computer users to be on their guard following the discovery of a new large scale malicious spam campaign posing as an email from courier firm DHL.

http://sophos-enterprise.blogspot.com/2009/03/spammers-exploit-dhl-in-another.html

 

Astaro today announced availability of version 2.0 of its Astaro Command Center.

http://astaro-security.blogspot.com/2009/03/astaro-command-center-20-improves-vpn.html

Virtual Graffiti, Inc
“Your source for Technology and Network Solutions”
http://www.virtualgraffiti.com

ParagonHost, LLC
“Home of VIP Hosting”
World Class Internet Solutions
http://www.ParagonHost.com

What is GRID Hosting Technology?

http://www.ParagonHost.com

Part of our infrastruture that powers ParagonHost and TheSpamBusters use’s Grid Technology from Media Temple. Here is a bit of “Tech” info on the Methodology of this Technology.

Anatomy of Storage on the GRID

March 6th, 2009 at 6:06 pm

A road to better transparency

Customers may remember that early generations of the GRID required significant changes to the way MySQL operated. The initial uptime on this service segment was not very good. Ultimately we solved the database problems and our discoveries led to the development of some highly unique auto-scaling technology. The series of events led us to become more transparent and write the article “Anatomy of MySQL,” which helped our customers understand our systems much better. We also made a full commitment to our Incident Status System, which has now tracked over 200 public-facing incidents.

We have been successful at improving transparency, but our customers are asking for more information. We intend to provide it. While our incidents have delivered a better level of accountability, they have fallen short in satisfying the deeper concerns our customers have regarding the ongoing storage problems.

Our oldest customers (the ones who tend to be early adopters and our most loyal) have been the group most seriously affected by the storage issues of our 1st-generation architecture. This doesn’t make us happy. Our original transition agenda has not worked out as planned and there have been many factors delaying us from migrating these customers to technology that is reliable.

We’d like to help you understand what’s going on now.

1st Generation vs. 2nd Generation

(mt) caters to intense customers so our storage systems need as much performance as possible. For the original GRID storage architecture we selected BlueArc’s Titan hardware, which continues to power our 1st-generation Clusters 1 and 2. Beginning with Clusters 3, 4, and 5 (mt) chose Sun Thumper and Thor equipment.

1st-Generation Architecture

(where last weekend’s incident occurred)

At the time, BlueArc Titan was the fastest storage technology available. Our research indicated that the system was extremely redundant internally — every cable, controller, disk, and front-end head was cloned. However, even with all of the failover protection we still had numerous issues with instability and crashes in firmware. Because every component is redundant, we assumed the system was protected from failures — however, there are 3 major reasons why, in our opinion, downtime still occurs.

1. Unreliable Failover
   In the case of a crash, our experience was that failover took an exceptionally long time (5-10 minutes.) Some of the crashes, such as the one last weekend, exhibited extra issues. Our assessment is that the bug that caused the first HEAD to crash (in this case, a corrupted filesystem) would cause the second HEAD to crash as well, essentially bringing the redundant system fully offline. This is not cheap equipment — we expected it to work.
2. Lack of OS Independence
   Originally we created a massive storage pool to serve both the cluster node operating system as well as User Data. Our design trusted this safe coupling because of the internal redundancies inherent in the BlueArc Titan. This also served an efficiency goal by reducing each cluster’s power footprint. In the end, when there were storage problems, every public-facing server had a high crash probability. Engineers would have to address both storage issues along with cluster node recovery. This design was a mistake on (mt)’s part and the practice has been replaced with a much better method.
3. Complicated Upgrades & Maintenance
   The firmware version in our BlueArc Titan makes upgrades take an extremely long time and require full-cluster downtime. This has led to maintenance windows far longer than we (or you) want for your services.

BlueArc Titan is an extremely robust system and it is fantastic at many things. The company’s engineering and support infrastructure is top-notch. However, we have had too many core issues and have consequently been forced to rethink our storage architecture completely. BlueArc is a tremendous company with a top-tier product, but, in our opinion, it is not the proper solution for our needs.

2nd Generation Architecture

Our new generation Clusters 3, 4 and 5 use a combination of a new storage design, along with more extensible storage technology powered by Sun Microsystems. Still fully hardware redundant on all levels, the combination of new design and the more flexible Sun equipment allows our new architecture to be more reliable. This architecture is currently in the process of being rolled out transparently to Cluster 1 and Cluster 2.

• Decoupled OS & Storage Segment Isolation
  If one part of the storage network has a problem, such as a runaway user process causing high disk I/O, it is isolated from being able to affect customers on other segments. Also, the root OS remains totally isolated so there is no degradation to cluster node performance. This, combined with a smaller number of customers per storage segment, leads to a far more reliable system. The possibility of a problem with one segment (such as we had this weekend) has much less of a chance to cause global problems.
• Better Caching
  People look at your site a lot more often than you change it, so we can actually cache quite a bit of your content for you in in the Storage Segments. Spinning mechanical disks are slow. We have increased our levels of cache more than 20x across the storage network. Our customers have already seen notable performance and stability gains because of this.
• Granular Diagnostics
  Using DTrace, a very powerful diagnostic tool in Solaris 10, we are able to conduct highly sophisticated real-time monitoring to catch incorrectly coded scripts or other unintentional issues that put excessive load on a given storage segment. This level of insight is not available in closed platforms, where real-time diagnostic tools tend to be limited to the vendor’s engineers.
• Quicker Backup Recovery
  In the event of a serious filesystem failure, under the old architecture recovery from backup was possible but took a significant amount of time (even with fast disks and 10 gigabit networking, copying 15 terabytes of data from one disk system to another takes hours). In the new architecture, backup servers have the same performance capabilities as their data source and they are larger in size. Even in the unlikely case that we need to revert to a backup, engineers can perform the task in minutes. 

Moving OLD customers to NEW technology

With all that being said, why are some of our customers still on the original architecture? It seems like they should have access to improved systems first right?

 

We needed to prove that our new designs were significantly better than the original designs. Even after receiving great results from our labs simulation, we elected to honor the lessons of the past. We have learned time and time again that real-world results always teach us things that are impossible to find in simulation.  To this end we launched Cluster 3 and began rigorous observation. Second, the original Sun hardware platform also displayed some hardware-related glitches once it reached production. This delayed implementation until we were sure that its successor, to which we have upgraded, had eliminated these issues.

So how are we proceeding with getting the remainder of Cluster 1 and Cluster 2 to this new, proven design?

Two major ways.

Upgrading Cluster 1 and Cluster 2

First, we are well underway with the in-place upgrade. The most time consuming part of this process is migrating the vast amounts of data from one system to another, while keeping the transfer rates and load gentle enough not to cause any performance issues to everyday operation. At time of writing, 37% of Cluster 1 customers, and 44% of Cluster 2 customers have already been migrated.

About a month ago, we dramatically accelerated this process and have purchased 100% of the hardware needed to complete the project. We anticipate that the entire process should be completed by 06/2009. Most customers will be on the new architecture much sooner than that.

Next 30 days, Cluster-to-Cluster migration tools.

We have committed significant developer and administrator manpower to the development of Cluster-to-Cluster migration tools. Currently, it is possible to migrate yourself to a new cluster, utilizing the technique described in our Knowledge Base . This method is complex and not highly recommended. The first version of the migrator tool will eliminate a lot of the manual steps.

We have good technology today. But, there is more to come.

Our 2009 storage road map is exciting. As our new architecture continues to prove itself, we are not stopping development of new technologies.

• Storage segment fencing In our 2nd-generation system, storage segments are more individually isolated and overall less likely to cause system-wide disruptions. Additionally we are in the late development phase of special “fencing ” software which adds an additional layer of protection when storage malfunctions. This software keeps the cluster healthy and functional even during extreme cases of disk turbulence.
• Storage-Eye View Using the powerful insight given to us by DTrace, we are developing automators that actually solve storage issues without human intervention. These self-healing tools are also being leveraged to provide customers with new reports and details concerning the behavior of their applications. Awesome.
• SSD Sun is pioneering the integration of SSD (Solid State Disk ) technology in a very interesting way with their Hybrid Storage Pool products. We are currently experimenting with this technology in our labs. The results are looking fantastic.

A final note about redundancy

We would like to communicate the exact current high-availability (HA) status of clusters with in our GRID:

Currently HA:

• Every drive. We have 100% RAID through the system.
• Every server.
• For storage segments and all other critical servers we have full internal redundancy (power supplies, fans, etc.)
• Load balancer, networking, and hardware.

Currently Not HA:

• Intra-cluster networking equipment, including cables. We have hot spares that can be activated within 5-20 minutes, but it’s not HA. We are considering changing this in our (cs) product but we are still debating the uptime advantages.
• Storage segments. We can fail over to the backup if needed, and we can typically recover from any other non-catastrophic issue within 3-5 minutes.
• Individual MySQL servers and Containers.

Summary

We understand downtime may represent a once in a lifetime, non-retrievable instance, so we are committed to producing more stable, flexible and powerful hosting.

(mt) Media Temple has committed to communicating with our customers more effectively as well. Given our recent stumble we clearly need to improve our communication systems. Soon we will further integrate our information flows with rapid-broadcast systems like Twitter and VoIP. We’re going to keep looking for ways to get you information quickly.

(mt) Media Temple aims to be a proactive and agile company working to address the varied needs of our clients. This is a serious promise.

Google Apps: February 2009 Newsletter

February 2009 Newsletter

Email, calendar and collaboration tools for your business

Table of Contents: Product Updates How are other customers using Apps? Tip for your users! Beyond Apps Hello Google Apps admins! Here is your monthly dose of Google Apps news and updates. We hope you enjoy it and pass on the word to your users. As always, we’d love to know what you would like to see in upcoming newsletters and welcome you to submit your feedback here.

What’s New Offline access for Gmail and Calendar Google Sync for your contacts and calender events New Google Earth with Ocean Additional Resources Google Apps Homepage Provide Feedback

Product Updates:

Offline access is now available for both Gmail and Calendar

We are happy to announce that within the past couple of weeks, we have rolled out offline access in Gmail Labs and read-only offline access as an option in Calendar for Google Apps customers. When you enable offline access for Gmail, it will load in your browser even when you don’t have an Internet connection. You can read messages, star, label and archive them, compose new mail and more. Messages ready to be sent will wait in your Outbox until you’re online again. Remember, we’re still working out kinks, which means you might see some issues that aren’t completely ironed out. But this is a major step along the way.

Now that you have offline access for Gmail all figured out with no or unreliable internet connection, you will also be able to see your events in Google Calendar from wherever you are. Offline Calendar will let you view your existing schedule and events, but not edit them, so you don’t have to print out calendars the night before a trip. Users of Google Apps Standard Edition can get started on these steps immediately.

For Premier and Education Edition, domain admins will have to enable Gmail Labs for offline access to Gmail before users can start taking advantage of it. For Calendar, domain administrators will first have to check the box next to ‘Turn on new features’ in the ‘Domain Settings’ page of the Google Apps control panel before their users can enable this option. This offline feature uses Gears, an open source browser extension that adds offline functionality directly to the browser.

Sync up your contacts and calendar events with Google Sync:

Google Sync is now available for users with iPhones or Windows Mobile devices. With Google Sync, whether users make changes to calendar events and contacts from their browsers or mobile devices, changes will be reflected in both places automatically, within minutes. And because Google Sync ties directly into devices’ pre-installed calendar and contacts applications, employees don’t need to learn a new interface.

To get started, Google Sync must be enabled for your domain from the Google Apps control panel. Then, employees will be able to configure Google Sync from their devices. The instructions for each type of phone are different, so check out our help center for device specific information.

Before getting started with this beta release, please take a minute to review some syncing limitations we’re aware of with the iPhone and Windows Mobile devices. Also, keep in mind that Google Sync will replace all existing contacts and calendar information on your phone, so make sure to back up any important data before you get started..

Google Sync is also available for users with Blackberry devices and phones that support SyncML. For more information, visit m.google.com/sync.

A new layer for data access security for Google Apps:

In addition to existing capabilities such as SSL options and single sign-on capabilities to help keep your information safe, we’re adding a new layer of security: the ability for administrators to set password length requirements and view password strength indicators to identify sufficiently long passwords that may still not be strong enough. What’s more, because the Google Account authentication system continuously sees new variations of password attacks from around the world, we can assess password strength in real-time and help administrators spot passwords that were relatively secure in the past that are more vulnerable to the latest patterns of attacks.

Premier and Education Edition administrators can access these features from the administrative control panel under ‘Advanced Tools’ > ‘Advanced Password Settings’.

Google Apps Authorized Reseller program is now open:

While Google Apps is easy to use and many businesses will continue to come to us directly online or through our Enterprise team, many appreciate the services provided by local firms who are intimately familiar with their particular needs. We’re looking forward to working with a broad range of partners, from VARs and IT consultants to professional services firms and global systems integrators, to ISPs and other SaaS providers. With over 1 million businesses and 10+ million active users in more than 100 countries, Google Apps adoption is set to accelerate even further in 2009. This provides partners with a great opportunity to expand their expertise into cloud computing while building profitable new businesses.

To learn more about the reseller program, please visit www.google.com/apps/resellers.

Get product update alerts by email:

If you’d like to be notified about product updates right as they happen, you can get alerts by email. To subscribe, visit http://www.google.com/apps/admin-updates.

How are other customers using Apps?

We recently uploaded a video tour of a corporate intranet built by one of our customers using Google Sites. Google Sites is an easy way to collaborate and publish web sites without any technical knowledge. It’s another way to help you get the most out of Google Apps — and save money at the same time. Watch the video to learn more about Google Sites.

Tips for your users!

Sending from multiple addresses in one account

If you have multiple email accounts, you can choose to send messages from your Google Apps email account using another address. For instance, if you own user@example.com and user2@example.com, you can send mail from either account. You can send messages using other addresses, too. This is called the custom ‘From:’ feature.

Keep in mind that this feature doesn’t configure your inbox to receive messages from another account. If you’d like to receive messages from another account, you’ll need to set up auto-fowarding in the other account. If you haven’t customized the ‘From:’ field in your account yet, check out http://google.com/support/a/users/bin/answer.py?answer=22370 for instructions.

Note: To send this tip to all users at your domain, forward this message to a domain-wide email list. If you haven’t yet created a domain-wide email list, visit the User Accounts section of the control panel. Click ‘create email list,’ enter a name for the list, and then click ‘Add everyone in my domain.’

Beyond Apps

Dive into the new Google Earth

Google Earth’s latest release includes new features Ocean, Historical Imagery, and Touring! Google Earth Pro allows professionals to visualize and share geospatial data and make better location related decisions. Layer your company’s data on top of Google Earth imagery with Google Earth Pro’s data import feature. Share additional context about areas of interest by adding HTML and javascript to placemarks. Make videos with Google’s new oceanic & historical imagery for use in presentations or on your website.

To learn more about Google Earth Pro, please contact us at ge_sales@google.com.

 

Email Preferences: We sent you this email because you’ve indicated that you would like to receive email notifications about Google Apps. If you don’t wish to receive emails like this in the future, please log in to the control panel, click ‘Domain Settings,’ and ‘Account information’. Remove the check beside ‘Email Notifications,’ and click ‘Save Changes’. 

Google Inc.
1600 Amphitheatre Parkway
Mountain View, CA
94043

 

ParagonHost
http://www.ParagonHost.com

News Aggregation and Managed Business Class Hosting

Technology News 01/27/09

Cisco today announced new products designed specifically for small companies

http://cisco-products.blogspot.com/

 

RocketStream Data Transfer Acceleration Software Now Available for Online Purchase

http://rocketstream.blogspot.com/

 

Dialogic Adds Analog PCIe Cards & Half-size Multi Span E1/T1 PCIe Boards to its Diva® Media Board Portfolio

http://eicon.blogspot.com/

 

Barracuda Networks Inc. today announced it has acquired Yosemite Technologies,

http://barracuda-networks.blogspot.com/

 

Eye Digital Security (www.eeye.com) today announced the availability of the Blink Security Management Appliance 200,

http://eeye-security.blogspot.com/

 

APC today announced the Modular Three-Phase Power Distribution Unit (PDU).

http://apc-guard.blogspot.com/

 

VirtualGraffiti, Inc

http://www.VirtualGraffiti.com

“Your Source for Security and Technology Solutions”

 

ParagonHost, LLC

http://www.ParagonHost.com

“Home of VIP Hosting”

Compare the 5 Most Popular IP Phones and More!

Adopting IP phones can deliver significant benefits to a business, whether its
improving employee productivity or delivering better customer service. Find out
which manufacturers and models deliver on this promise.

Download this guide now to learn more, compliments of VOIP-News:

http://www.topica.com/f/v.html?1700074809.1700030538

If you found this resource valuable, you may also be interested in the following:

**Compare Top Hosted PBX Phone Systems From Vendors like Aptela, Packet8 and Covad

  The VoIP News Hosted PBX Comparison Guide looks at hosted PBX systems from leading
  vendors like Packet8, Aptela, Covad, Bandwidth.com and others to help you make a
  straightforward comparison as part of your research and evaluation of which system
  to invest in.

  http://www.topica.com/f/v.html?1700074809.1700054376

**Compare Hosted PBX Systems For Small and Medium Businesses

  The VoIP News Hosted PBX Buyer's Guide covers the important features, benefits,
  technologies and market background to help you make sense of this confusing market
  and narrow your search down to the vendors that can really solve your communication
  problems.

  http://www.topica.com/f/v.html?1700074809.1700054375

**The Phone System Buyer's Guide

  Take a look at the basic issues and find out what you need to know to make an
  informed choice.

  http://www.topica.com/f/v.html?1700074809.1700034106

**VoIP Call Center Buyer's Guide

  Learn everything you need to know about choosing a VoIP call-center solution in
  this Buyer's Guide. This white paper address topics such as: Major vendors, Basic
  and advanced features, and Cost.

  http://www.topica.com/f/v.html?1700074809.1700035292

To view other IT resources, visit the library at http://tek-tips.nethawk.net/

What Features are gained by each level of MICS upgrade

Source: http://www.tek-tips.com/faqs.cfm?fid=5388

What Features are gained by each level of MICS upgrade faq799-5388 Posted: 13 Aug 04 (Edited 14 Mar 05)

Features to be gained by upgrading: The following features may be gained by upgrading the MICS from a lower level, (starting at MICS R1T1), to a higher level, (either 1.0, 1.1, 2.0, 3.0, 4.0, 4.1, 5.0, 6.0 or 6.1). Please note that not all features to be gained are available with all levels of revision/upgrade. Also note that upgrading to Version 6.0 or higher requires upgrading the NAM (Voice Mail) as well. 1) Administration & Configuration tree (new programming structure) – Does not effect end user. (available for MICS 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 2) Alpha Tagging – Tags System Calls with name and number. (available for MICS 6.0; 6.1) 3) Analog Station Module Recognition – Allows for installation of Eight analog stations at a time. Please note: analog stations can currently be added to MICS 1.0 via Analog Terminal Adaptors, however one adaptor is needed per analog terminal/phone.  (available for MICS 1.1; 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 4) Automatic Daylight Savings Time – System automatically switches time between Daylight Savings Time and Standard Time.  (available for MICS 1.1; 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 5) Call Park Codes (25 instead of 9) – Allows users to park up to 25 calls at a time instead of just 9. Call park is a system wide “hold” where users dial a 3 digit code from any phone to retrieve the call. (available for MICS 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 6) Round Robin Park Code Assignment – Park Codes can be assigned in a round robin fashion versus always starting at the first code. (available for MICS 1.1; 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 7) CLID On All Target Lines – All Target Lines will show Caller ID. (Note target lines require DID trunks). (available for MICS R1T1; 6.0; 6.1) 8) CLID When Busy – Incoming Caller ID will be displayed on the users set even when a user is on another call. (Requires target lines/DIDS) (available for MICS 4.1; 5.0; 6.0; 6.1) 9) 300 Caller Logs – CLID logs = 300 total for entire system. (available for MICS 1.1) 10) 600 Caller Logs – CLID logs = 800 total for entire system. (available for MICS R1T1; 1.0; 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 11) Copy Settings for Control Sets and Lines – Makes programming some settings much easier for Maintenance personnel. Does not effect end user.  (available for MICS R1T1; 6.0; 6.1) 12) Destination Code Length – Maximum allowed digits increases from 7 to 12. This is a feature associated with Least Cost Routing which allows dialed digits to be matched against a table for most cost effective routing. (available for MICS 6.1, R1T1) 13) Distinctive Line Ringing – Can assign one of four distinctive ringing patterns to a line. (Note that once a distinctive ring is assigned to a particular line, at any phone set, that ring it cannot be used for any other line, on any other set on the system). (available for MICS 6.0; 6.1) 14) Hunt Group Distinctive Ring – Hunt Groups can be assigned one of four distinctive ring patterns/tones. Please note that once a distinctive ring is assigned to a hunt group it cannot be assigned to another hunt group or any other lines. (available for MICS 6.0; 6.1) 15) ETSI Network Call Redirection – European Networking Feature. Not applicable to North America. (available for MICS 1.1; 6.0; 6.1) 16) External Call Forward – Calls to Stations can be forwarded to external numbers. (Not to be confused with Line Redirection which allows Lines appearing on a given set to be forwarded, or redirected, to an external number) (available for MICS 4.1; 5.0; 6.0; 6.1) 17) Hospitality Services – Typically Used in Hotel/Motel environments, provides features such as Alarm Clock (for wake-up call service), Room Condition (for letting maid service provide front desk indication of whether or not a room has been cleaned), and Room Occupancy (works with room condition to allow front desk personnel to assign occupancy condition and restriction filters to room phones).  (available for MICS 4.1; 5.0; 6.0; 6.1) 18)  Hunt Groups – Enable a single extension number to be used to call a group of sets. Hunt Groups replace Incoming Line Groups on MICS 4.0 and higher). Improves call answering coverage and allows calls to ring in independent of individual stations Voice Mail Coverage and Call Forward assignments. (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 19) Incoming Line Groups - (See Above) (available for MICS 1.1; 2.0; 3.0) 20) IDM Support – Allows for installation of Integrated Data Modules which will allow Ethernet LAN connectivity for up to 12 Ethernet devices to the ICS and allows WAN bridging and routing via T-1 which can be shared between voice calls and data traffic. (available for MICS 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 21) ISDN BRI and PRI support – ISDN technology provides a fast, accurate and reliable means of sending and receiving Voice, Data, Images, Text and other information through existing analog telephone wires. Both PRI and BRI also allow for out of band signaling for faster call setup and tear-down, as well as higher bandwidth and speed than analog transmission because of its end-to-end digital connectivity on all transmission circuits.  There are two types of ISDN service BRI and PRI BRI has 2 Bearer Channels and 1 Data Channel  PRI has 23 Bearer Channels and 1 Data Channel. Bearer Channels can carry voice and data and have speeds of 64kbs per channel. The D-channel provides for call set-up instructions and signaling, also known as out-of-band signaling, and feature activation information at speeds of 16kbps for BRI and 64 kbps for PRI. Data information consists of control and signal information and packet switched data, such as credit card verification. Both BRI can provide dial-up internet and LAN access and a PRI can be used to Network the MICS with a Meridian 1 or other MICS units. The PRI can also be used in conjunction with DID’s and/or Dial out pools to provide a more cost effective means of Trunking as each PRI can provide call-by-call service for up to 23 simultaneous calls. (available variously for MICS 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1  – see below for specific features and types of service) 22) BRI Basic Call Trunking – Trunking in calls over a BRI connection. (Can receive incoming calls from the public network via the BRI loop). (available for MICS. 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 23) BRI Calling Name ID – Will display network name of parties involved in a call. (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 24) BRI Calling Number ID (Incoming Calls only) – Will display number of calling party. (available for MICS 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1)   25) BRI Subaddressing – Can perform sub-addressing of Terminal Equipment on the same BRI loop. However, terminal equipment which supports sub-addressing is not commonly available in North America. (available for MICS 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 26) PRI Basic Call Trunking – Can receive incoming calls from the public network via the PRI circuit. (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 27) PRI Calling Name ID – Will display the network name of calling party. (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 28) PRI Calling number ID – Will show the number of the calling party as long as it is provided by the public network. (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) Will Show Caller ID while on another call. (available for MICS 6.0; 6.1) 29) PRI Call-by-Call Services and Fractional PRI – Allows a user to access services or private facilities such as Foreign Exchange, Tie Lines and OUTWATS without the use of dedicated facilities for these services. The number of channels dedicated to each call type can be programmed from 0 to 23 which also allows for use with a Fractional PRI by disabling unused channels. (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 30) PRI E911 – When calling out through the PRI the telephone number AND the internal extension number of the calling party is transmitted to the Public switched Telephone Number. Allows for more accurate location identification of a caller by the PSAP (911 center) when used in conjunction with DID lines and OLI (Outgoing Line Identification) (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 31) ETSI MCID – European Telecommunications Standard Institute Malicious Caller ID Support. The Malicious Caller Identification (MCID feature enables a called party inside an enterprise network to use a configurable sequence of digits to notify the local law enforcement agency of a malicious call. This is for the European Standard. (available for MICS 6.0; 6.1) 32) Static Time and Date – Constantly shows current date and time on display. (available for MICS 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1)   33) Networking Norstar to Meridian 1 – Allows for Networking the MICS to a Meridian PBX with the following features listed below: (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 34) Networking to Meridian 1   Centralized PSTN – Allows for centralized Trunking through the Meridian 1 to the PSTN. This lets the Meridian 1 handle all the routing for the MICS and allows for concentration of resources for cost savings. (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 35) Networking to Meridian 1   Coordinated Dialing Plan (CDP) – Allows for a Coordinated or Transparent Dialing Plan on the network where all DN number on the entire network are unique and of a uniform length. (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 36) Networking to Meridian 1   Name and Number ID – The name and number of all parties involved in a network call are displayed. (available for MICS 4.0; 4.1; 5.0; 6.0; 6.1) 37) Networking to Meridian 1   MCDN (Centralized Voice Mail) – Allows for all network voice mail to be centralized to help reduce costs and to allow the sharing of messages between systems on the network. (available for MICS 5.0; 6.0; 6.1) 38) Networking to Meridian 1   MCDN ICCL – ISDN Call Connection Limitation. Limits the number of hops to a defined transit counter to prevent the creation of a continuous loop. (available for MICS 6.0; 6.1) 39) Networking to Meridian 1   MCDN TAT – Trunk Anti Tromboning. Prevents unnecessary use of system resources when transferring active calls back and forth over the network by eliminating redundant paths between systems. (available for MICS 6.0; 6.1) 40) Networking to Meridian 1   MCDN Camp-On – Allows an Operator on the Meridian 1 to camp-on a call across the network to a networked KSU (MICS). (available for MICS 6.0; 6.1) 41) Networking to Meridian 1   MCDN Break-In – Allows an Operator on the Meridian 1 to Barge-In on a call through the network to a station on a remote KSU (MICS). (available for MICS 6.0; 6.1) 42) Networking   Norstar-to-Norstar - Allows for Networking Norstars MICS together with Centralized features such as Voice Mail, Attendant, Applications and management. (available for MICS 6.0; 6.1) 43) Outgoing Name/Number Blocking – Users can send outgoing name/number blocking header to PSTN on a call-by-ball basis. Name and Number will not be displayed at the receiving end. (available for MICS 4.1; 5.0; 6.0; 6.1) 44) Page Time-Out – A timer can be set so that once a page is initiated, the timer starts and will end the page connection after expiration of the timer. Helps prevent inadvertent lock-up of the paging in an open, or on, condition. Also helps deter obnoxiously lengthy pages. (available for MICS 1.1; 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 45) Page Tone On/Off – Allows for enabling or disabling the page preannounce tone. (available for MICS 1.1; 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 46) Private Networking – Allows for networking the MICS without using the PSTN to provide such feature as a Common, or Coordinated, Dialing Plan; Centralized Voice Mail; Centralized Trunking; Centralized Attendant; Sharing of Single Application and Resources to improve ROI, and easier management since applications can be managed as a single unit. (available for MICS 5.0; 6.0; 6.1) 47) Centralized Voice Mail on Norstar – Allows one Norstar to host the Voice Mail for the entire Network and thus provide for easier interface between all voice mail boxes and their users. Also reduces Costs as Voice Mail unit is not needed for each MICS in the Network (available for MICS 6.0; 6.1) 48) Centralized Auto Attendant on Norstar – Allows one Auto Attendant to handle all the Calls for the Entire Network. This saves money as only one Auto Attendant need be purchased for all the MICS/Norstars, and also provides outside callers with for easier and seamless progression through the network via the Centralized Auto Attendant. (available for MICS; 6.0; 6.1) 49) Routing Service Routes – Allows Routes to be defined for various Destination Codes. Often associated as Least Cost Routing, the MICS automatically sends/Routes a call to specific trunks depending on the digits dialed. Earlier on only 1 route could be defined for each Destination Code. The number of routes available was later increased to 3. 1 Route - (available for MICS 1.0, 1.1; 2.0; 3.0; 4.0; 4.1; 5.0; 6.0) [/b]3 Routes – [/b](available for MICS 6.1) 50) Silent Monitoring for Hunt Groups – Allows for Silent Monitoring of a hunt group call by a supervisor to ensure quality. Also allows for training of new call handling personnel by allowing them to listen into proper call handling procedures. (available for MICS 6.1) 51) System Speed Dial – Increase in number of entries from 70 to 255. (available for MICS 6.0; 6.1) 52) Station Set Test – Allows test of buttons and ringers on an individual set (available for MICS 2.0; 3.0;4.0; 4.1; 5.0; 6.0; 6.1) 53) System Wide Call Appearance – Allows for the appearance of parked calls on programmed line buttons. A button must be programmed for each park code the user wants to appear. (available for MICS R1T1; 6.0; 6.1) Special Thanks to Mike Cronin for his assistance with this information.