Recently in SIP Category

Today the covers came off our new Multi-Service Business Gateway (MSBG) product and our roadmap to connecting SIP Service Providers and SIP Enterprises together.

What is an MSBG you ask?  A multi-service business gateway is the union of five distinct functions that to date required separate boxes.  Network Access, Routing, Session Border Controller, VoIP Gateway and Application Server all in one device.

Why one device?  Today service providers and large enterprises need these separate functions, but stacking a number of boxes from different vendors has some real problems.  The most significant problem is defining the point of demarcation - where does the service provider's responsibility end and the customer's responsibility begin?  Installation, wiring and management are a real headache too.  Each new wire is another place for a loose connection, accidental unplug or a broken cable. 

What are the applications?  Service providers and large distributed enterprises would benefit the most from this new product. 

How do I learn more?  We've put together a number of resources to help educate our readers about this new platform:

Web landing page:  www.audiocodes.com/MSBG 
Press Release can be found here.
We are also hosting a webinar June 4th that you can click here to register.
We're also going to have the product at the following trade shows this next month:

NXTCOMM, 16-19 June 2008 at the Walker and Associates Booth #SU10416 and the NEI Booth #SL3924
INFOCOMM, 18-20 June 2008 at the ScanSource Communications Booth #N5963
CommunicAsia, 17-20 June, 2008 Booth#4G4-07

I'd love to have you participate in either one of the webinars or events to learn more about this exciting new development.

What others are saying about the AudioCodes Mediant 1000 MSBG:

Another great turnout for today's two webinars on "Fax - SIP+T.38 to the Rescue", thanks everyone for participating.

And more great questions:

Q: (Brian) a slide showed FAX machine - T.38 gateway - T.38 Gateway - FAX Machine.  I was under the impression that once a FAX was converted into T.38 It coudlnt be changed back into a audio FAX call.
A: Actually, a fax can be converted to T.38 and back no problem or loss of information.  This is what happens with virtually all fax calls that are transported over VoIP carriers.  It works fine.

Q: (Darren) Do your gateways support V.34 fax over T.38? Does your T.38 fax SDK? If not, where is this on your development roadmap? We have identified this as one of the major monetary objections to using T.38 instead of TDM.
A: Our T.38 Fax SDK does support V.34 transport, but at this time our gateways are limited to V.17 speeds when used with T.38.  We are working toward delivering V.34 with T.38 on our current gateways and hope to announce our formal plans soon.

Q: (Darren) Is your T.38 fax SDK available for Linux?
A: Our T.38 Fax SDK is for Windows, but there are many others on the market and do believe a few of them support Linux.  We've had many customers use T.38 SDKs from one vendor and our gateways with no interoperability issues.

Q: (Yaniv) When using an analog MediaPack gateway, can the DID/DNIS information be passed to the SIP application?
A: Absolutely - is appears in the SIP INVITE.

Q: (Roger) Will these slides/audio be available?
A: Yes, a previously recorded version of the webinar is available at: http://www.tmcnet.com/webinar/audiocodes5/

Just as a reminder, the questions from the previous session can be found at:  http://blog.tmcnet.com/sip-invite/sip/fax-webinar-qa.asp

You can address your questions to me at:  alan.percy@audiocodes.com

Thanks again to all those that participated in the Webinar titled "Fax - SIP+T.38 to the Rescue" we held a few weeks ago.  As noted in a previous blog post, it was a very busy webinar.  You can listen to the on-demand recording of the webinar at: http://www.tmcnet.com/webinar/audiocodes5/

As noted on the webinar, we had run out of time and were unable to get to all the great questions posed by the attendees. Find below some of the Questions and Answers that we didn't have time to address:

Q: (from Scott) is T.37 being employed and deployed?
A: T.37 is used in some messaging applications, but it is quite different than T.38.  T.37 uses email technology to transport documents and thus is not real-time.  It's great for store and forward applications, but not widely used or supported by carriers. For more on T.37, visit wikipedia

Q: (from Scott) who offers T.38 SDK's for fax API's?
A: AudioCodes and a number of other manufacturers offer a T.38 SDKs.  AudioCodes has certified our gateways with a number of other other third-party manufacturer's T.38 software.

Q: (from Tim) I think T.38 was specified to use "UDPTL" or TCP - with RTP only added to the spec recently. What do people use in practice?
A: We are using UDPTL, TCP adds addional timing issues into the equation.

Q: (from Jayaprakash) Does Gateways always do the Fax tone detection? or it is Fax Application server responsibility?
A: Our gateways can detect the CNG fax tone, which makes fax detection much easier for application developers.  Detection can be done by the application servers, but it is much harder and less accurate.

Q: (from Oliver) Which SIP trunking carriers support T.38?
A: AT&T and Quest are two carriers which have been certified to work very well.  Others are in lab testing.

Q: (from Edward) How much bandwidth required for SIP+T.38 normally ?
A: T.38 with triple redundancy and operating with V.17 speeds would use roughly 48 kbps.  Less redundency on good networks would use even less.   In comparison, a fax over G.711 would require close to 80 kbps.

Q: (from Prashanth) Can T.38 fax be done using other codecs than G.711?
A: No, transporting fax via T.38 is done instead of using a voice coder (like G.711).  Other voice coders compress the audio and are even less reliable than G.711.

Q: (from Yossman) Is your media gateway compatible with other brand devices that also supports SIP+T.38 ?
A: Yes, AudioCodes media gateways are many times deployed in mixed network environments and have excellent compatibility and reliability.

Q: (from Shawn) do you need to have a t.38 media server on both sides (sending and receiving)?
A: For T.38 to work, both ends of the IP connection need to support T.38

Q: (from Anil) Does these Media Gateways also have similar issues like Denial of service and other attacks and how do we solve this?
A: (While not the topic of this thread, this is a good question) Security is always a big concern and media gateways do need to be hardened to protect against attack.  AudioCodes gateways have been hardened and passed stringent DoD certifications for deployment in DoD networks. 

There are many more questions and I'll post more in the next few days....

After yesterday's webinar on fax, I'm overwhelmed. 

When we were developing the plans and presentation materials for yesterdays webinar titled "Fax - SIP+T.38 to the Rescue", our expectations were that a few "fax gurus" would join in and we would have a small very focused 20 - 30 person session on a rather deep dark secret of the industry.  Can you imagine my surprise when during the first few minutes of the session the participant count kept climbing and climbing to over 160 people!  Talk about standing room only. 

After 45 minutes of presentation and another almost 30 minutes of Q/A, I was toast.  There were some fantastic questions that I was able to address, but because of time limitations, we were unable to get to dozens more great questions.

The session moderator, Erik Linask published a great summary of the webinar.

What does this mean?  It can mean only one thing - there is serious pain in the VoIP industry when it comes to delivering reliable fax services and people are looking for solutions.

So what can I do to help close the gap?  I've decided to use this forum to provide both a recap of the webinar and address the many questions you in the audience posed both during and after the session.  This concept of tying both the webinar and companion blog together is a new experiment, so let's give it a try.  If you have questions and didn't get a chance to pose them during the session, you can send them to me at: alan.percy@audiocodes.com

I'm starting to work on the whitepaper version of the presentation, posting pieces in this venue as they are ready.   Once the completed whitepaper is ready for download, we'll be posting it on the TMC whitepaper library.

In the mean time, the abstract for yesterday's webinar:

Fax continues to be a key communications medium for many enterprises and service providers alike. Financial institutions, real-estate, government, law offices, and many others still depend heavily on fax to transfer thousands of documents daily into and from business-critical document management and ERP systems. Many service providers and enterprises have only recently recognized the challenges associated with delivering reliable fax documents over IP networks. What are the reliability issues with fax over G.711 and how can SIP and T.38 improve the reliability? Is there a way to eliminate the expensive dedicated fax boards? How can legacy TDM fax systems connect to SIP trunking carriers? How is fax document security addressed? What is the future of fax? This session will address these questions and many others, showing how SIP and T.38 can be leveraged to create reliable and scalable fax solutions for both enterprises and service providers.

For those that missed the live event, you can listen to the on-demand version at any time.

For those of you that have been following our series of webinars on SIP-enabled applications, we just posted my most recent whitepaper on conferencing / collaboration applications:

SIP Conferencing/Collaboration
Global organizations utilize conference calls as a very important business tool for collaboration. Multi-branch organizations were the first to recognize the value in voice and video conferencing services to economize on travel costs and to coordinate business activities. Other smaller organizations have also begun to recognize that having access to easy-to-use conferencing resources speed up collaboration efforts with clients and suppliers. Whether using a traditional TDM PBX, an IP-PBX or a hosted service provider, SIP is seen as a key technology going forward to help tie organizations together and dramatically reduce the costs of conferencing.

As voice is virtually ubiquitous in all conferencing applications, this whitepaper will focus on the voice component, whether from PSTN callers or from web-based conference clients. We'll save the other media types for future whitepapers

Click here to download your own copy.  Happy reading!

After spending this fall at a number of industry events, talking to customers and giving some serious thought to the topic, it's now becoming clearer how SIP trunking will really play a role going forward.

First, a couple observations / predictions:

#1 - SIP Trunking is really a misnomer - it really should be "Media Gateway Service Provider".  Think about it - if you really distill it down, the concept of SIP trunking is just about where the media gateway resides and who owns it.  For the foreseeable future, the vast majority of calls from your home/office will terminate on a PSTN phone somewhere.  I'd guess that 98% or more calls still terminate on PSTN circuits.  This means that virtually all calls must go through a media gateway somewhere to get to the PSTN - so it's really about who owns the equipment.

#2 - SIP Trunking is about consolidation - much like many other business models, the opportunity is in consolidation of traffic, sharing common media gateway infrastructure across a number of subscribers.  So instead of each business owning their own media gateway and PSTN lines, if you can get businesses to share a larger media gateway, you make money while they save money. 

#3 - "Security" Dare I say it? - very few SIP trunking service providers have really nailed the security puzzle of SIP trunking correctly.  Most push the problem to someone else or depend on ineffective SIP firewall products.  IMHO - this is like TJ Max depending on WEP to secure their credit card transactions -  a corporate disaster waiting to happen.  Any CIO worth their salt will make sure to have a Session Border Controller (SBC) protecting their organization from outside attack.

#4 - Tragedy of the Commons - by building a business model that depends on consolidating customer's traffic together through a common resource, someone eventually pulls out their Erlang calculator to figure out the usage factor and number of ports available for all the subscribers/customers.  This may be fine for some customers, but most of the customers that are really enticed by cost reductions don't want or can't share resources with others.  Think call centers or financial services - applications that push thousands of calls per hour into the network. 

#5 - The numbers may not add up - for many organizations, the cost of securing their SIP trunks and the service levels required of their SIP trunking service provider will wipe out any potential savings.  I've sat with customers and helped them do the math - it doesn't work in many cases.  However, for others, it does work - their needs are different and the model does work, even with the costs of security and dedicated bandwidth.

#6 - SIP Trunking is just a stepping stone - In the end, peer-to-peer SIP is where we are all headed.  We don't need a middle man to deliver our email, why do we need one for real-time voice and video conversations? I can easily envision enterprises using similar techniques we use today with email to call from enterprise to enterprise - all via SIP.  In the end, SIP trunking will be a transitional technology to reach those on "the old PSTN".  Think SkypeOut. 

I'd love to hear your comments, feel free to post them.

As part III of our continuing series on building applications based on SIP, I'm hosting a live webinar next week to show how SIP fits into conferencing and collaboration solutions.

Building Applications with SIP - Conferencing / Collaboration Solutions

Thursday, November 8, 2007, 2:00pm ET 11:00am PT

Global organizations utilize conference calls as a very important business tool for collaboration. Multi-branch organizations were the first to recognize the value in voice and video conferencing services to economize on travel costs and to coordinate business activities. Other smaller organizations have also begun to recognize that having access to easy-to-use conferencing resources speeds collaboration efforts with clients and suppliers. Whether using a tradition TDM PBX, an IP-PBX or a hosted service provider, SIP is seen as a key technology going forward to help tie organizations together and dramatically reduce the costs of conferencing.

By attending this webinar you will learn how SIP can be leveraged as a key enabling technology for conferencing and collaboration applications - delivering scalable and cost effective solutions while avoiding restrictive and expensive API development.

If you'd like to participate in the webinar, click here to register.