Packetizer News

The Questions of ITU-T SG16 WP2 (i.e., the groups focused on H.300-series standards, multimedia architecture, etc.) will be meeting in Geneva from 20-24 February 2011. The meeting is listed on the Packetizer Calendar, as most meetings are.

However, what makes this meeting different is that document registration and tracking will be done via Google Docs as an experiment. A special SG16 page has been created on Packetizer containing general information about SG16 WP2, along with mailing list information, room allocation information, and document registration forms and lists.

If you are unable to access Google Docs, do not worry. The documents will ultimately be stored on the ITU’s servers, just as all other meeting documents are stored.

Packetizer is pleased to announce the creation of a set of specifications referred to as the Packetizer Open Community Specifications (POCS). These specifications are intended to document new protocols or extensions to existing protocols that are created by the public at large.

The first specification published (POCS-1) is titled “Using OPTIONS to Query for Operational Status in the Session Initiation Protocol (SIP)” and is a document the authors tried to publish through the IETF. It failed to gain traction, not because equipment manufacturers are not implementing the procedures (they are, actually), but because trying to get consensus in the IETF is sometimes like herding a bunch of cats. Rather than expending significant effort trying to jump through hurdles, the authors decided to publish the specification so there is a permanent record, but outside the IETF.

The second document published (POCS-2) is titled “Transmission of a Session Capacity Estimate (SCE) to Prevent Session Initiation Protocol (SIP) Server Overload” and represents a valid and proven approach to preventing overload of SIP entities, particularly devices like Session Border Controllers. In this case, the IETF opted to limit the scope of their work such that SBCs and similar devices could not benefit from the defined overload mechanism. Specifically, the scope of the work in the IETF was on stateless entities like stateless SIP proxies. In the real world, there are many SBCs and a better approach is needed.

Packetizer would like to extend an invitation to the Packetizer community to publish new and different specifications as POCS documents. The type of documents that would be accepted include anything that might be of interest to the Packetizer community, including extensions to existing communication protocols, new web protocols, protocols for cloud computing support, etc.

Earlier this year, work on AMS, the ITU-T’s next-generation multimedia communication system, was conducted through electronic meetings held twice each month. As the SG16 meeting at the end of July 2010 approached, the meetings were suspended. It is now time to resume those meetings and a meeting schedule has been posted to the Packetizer Calendar page.

The electronic meetings are open to all who are interested in helping to progress the work on the revolutionary new multimedia system. Part of the time during the first meeting, to be held October 5, 2010, will be spent bringing participants up to speed on the work done so far, what work is currently being actively studied, and what needs to be done. Subsequent meetings will consider contributions submitted by participants as they are submitted.

If you have any questions or wish to engage, visit the site www.h325.com for more information, including subscription information to the mailing list.

The University of Wisconsin-Madison will offer its very popular course Understanding and Troubleshooting Videoconferencing Networks on November 2-3, 2010. The course will be held on the University campus in Madison, WI and will also be available via live videoconferencing.

By attending this course, you will master the H.323 standard and embedded protocols and then extend this understanding to SIP based and proprietary systems. Topics include:

• H.323 standard: components and functions
• Call signal processing and audio/video data flow
• QOS: options, implementation issues
• How ITU H.323 relates to IETF SIP and MGCP/Megaco
• Options for handling firewalls in the network
• Addressing and directory services
• Performance characteristics of various audio and video codecs
• Network security and other advanced features
• High definition videoconferencing options and content display
• Troubleshooting and analysis tools and techniques
• Understanding audio and video compression technology

Your course instructor, Gary Thom, is President of Delta Information Systems, a recognized expert in the field of videoconferencing, and the author of versions 1 & 2 of the H.323 standard.

Reserve your space today!
Call toll-free 1-800-462-0876
Or online at http://epdweb.engr.wisc.edu/courseL800

ITU-T SG16 initiated work on the study of Telepresence systems with the creation of a new experts group (or, "Question") focused on the topic. For more information, you might wish to subscribe to the itu-sg16 mailing list (see http://lists.packetizer.com/) and review the complete text of the new Question.

We have reported several times about our email server being blocked by spam-fighting organizations. While most organizations are quick to respond, some refuse to address the issue and others refuse to even talk to us about the issue. What's most frustrating is that our mail server does not send spam.

We are still blocked by SORBS, who told us without hesitation that, until Amazon pays them money, they're not going to unblock our address. The way they phrased their demands, it sounded like extortion to us. Apparently, they block all Amazon IP addresses and, since our mail server operates in the Amazon EC2 cloud, customers of SORBS are unable to participate on mailing lists we operate on Packetizer, specifically lists.packetizer.com.

More recently, Symantec has become a problem. Sadly, this is an organization that we could generally consider more reputable than others. Unfortunately, the company decided to block our mail server by assigning it a 'bad' reputation. This has affected Ericsson and perhaps other companies that would normally participate in ITU-T SG16 activities.

We tried contacting Symantec and they told us that they will not correct the problem, since we are not their customer. We've tried to explain that their customers are entirely unaware of the fact that they are being blocked, but they did not care. We alerted Ericsson once we became aware of this issue, but we do not have any way of knowing if other companies are blocked due to use of Symantec's Brightmail or other spam blocking services or products offered by Symantec.

If you attempt to join a mailing list on Packetizer and never get a response indicating that you successfully joined and your company uses Symantec products or services, then Symantec may be to blame.

OpenID is a web technology that allows a user have a single user identity and password that may be used to access any number of web sites, thus removing the age-old problem of having to maintain separate login and passwords for all of the various accounts on has on the Internet.

It is now supported by many web sites, including Google, Slashdot, Blogger, Flickr, Yahoo, Orange, MySpace, WordPress, AOL, and Facebook. Some of those organizations are 'identity providers', while some are end-user sites that rely on the identity providers to allow users to gain access to site content.

We produced an OpenID identity server software package for anybody who might be interested in running their own identity server. Perhaps equally important, though, is that we also added support to Packetizer Forums so that one may use OpenID to login, post questions, or reply to questions.

We hope OpenID support proves to be a popular and valuable service to the Packetizer Community.

At the most recent meeting of ITU-T SG16, the H.325 experts decided to initiate a series of electronic meetings in order to help progress the work. For those interested in participating in the creation of this exciting new multimedia system, see the meeting notice posted on the h325-design mailing list.

As we reported earlier, a number of spam-fighting organizations decided to block part or all of Amazon's EC2 service. This caused significant disruption to the mailing lists that we operate on Packetizer's mailing list server, including which provides list services for those working on ITU-T related work.

This past month, Spamhaus decided to block all of Amazon, in spite of the fact that we had previously submitted our IP address for removal at Spamhaus. That resulted in about 30 people getting kicked off of various mailing lists. So, if anybody reading this is wondering why you have not received email in a while related to H.323, H.325 or other protocols, Spamhaus might be the reason.

Fortunately, Spamhaus and Amazon quickly reached an agreement on how better coordinate in order to ensure that all of Amazon's EC2 IP addresses are not blocked again. To that end, Amazon now requests all mail servers to be registered with Amazon, which of course we did immediately. Amazon reviewed our request and granted authorization to use the server in order to transmit email.

On or about the same time, unfortunately, Amazon was also listed in MAPS and SORBS, two other spam-fighting organizations. We visited the MAPS web site, provided our IP address, and were almost immediately removed from their list.

SORBS, on the other hand, has been a real problem. The organization absolutely refuses to unblock Amazon EC2 or our individual address. We contacted SORBS and, while they were responsive, their reply was less than satisfactory. One of the more polite statements was:

You are not required to make a donation for delisting as the entry was not generated because of your actions, however the listing will not be removed until your service provider terminates the spammers or makes the required donation.

That is perhaps the closest thing we have ever seen to extortion. Sadly, while we continued to have a friendly dialog, after 20 days our mail server is still blocked by SORBS. It would appear they have absolutely no intention of removing Amazon EC2 and we do not believe that Amazon has any intent to work with them either. We can only suggest that if your company is using SORBS, you consider using an alternative blacklisting service.

The ITU approved a new revised version of Recommendation ITU-T H.323. H.323 is the most widely-deployed IP-based multimedia communication system in the world, used in videoconferencing, telepresence systems, and by service providers for international VoIP calls.

For more details, see the what's new in H.323v7 page.