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January 2002


Is Convergence Playoff Bound?


It�s October, and the baseball playoffs are here. This is the time when players and teams show how good they really are � where a pitcher nabs the corner for strike three with the bases loaded and two outs in the ninth or an unsung hero rises to the occasion to hit a game-winning home run. It is also the time for each playoff contender to show that the adversity and difficulty of the regular season has not been for naught and that every effort to win would be put in so that they might earn the World Series ring. And more importantly, each player would contribute to that victory.

For many years now, the Internet telephony world has meandered in the regular season, and the playoffs still seem a ways a way. However, we are no longer playing the first few games of the season. We are now more than midway through the season, and the quality of the latest VoIP equipment has shown me that we have a winning record. To make the playoffs, we must continue to pitch good products, hit for consumer appeal, and work together as a team so that the industry can win.

One of the biggest areas to throw us curve balls in this industry are issues in interoperability, where equipment from one company may not work with someone else�s product. That�s why ConvergeNET was originally created � not only to attempt to prove interoperability among vendors but also to work out the kinks on the way there. In this effort, our sixth ConvergeNET, which took place at INTERNET TELEPHONY� Conference & EXPO from October 4th-5th, showed more progress than ever before, telling me that we are playoff bound.

On my team for this important game were Agilent Technologies, AltiGen Communications, Anyuser.Com, Indigo Software, Mitel Networks, Nuera Communications, Quintum Technologies, and Unidata Communications. From the bench, we could also call on equipment from 3Com, Cisco, Mediatrix, PingTel, Polycom, and Siemens. We were ready to play and attempt to defeat �non-interoperability� from our field � the beautiful Hotel Del Coronado.

Before running onto the field to take our positions, we had to prepare ourselves mentally for the game ahead. In effect, NetIQ sang the national anthem by providing us with the Mean Opinion Score (MOS) for the network. The score was determined by using NetIQ�s new VoIP Manager Suite and the Call Performance module. NetIQ loaded the software agents onto two laptops on the show exhibit floor. Then, they configured the agents to emulate VoIP traffic using the G.711 codec. This showed in real-time that the network was consistently performing well for VoIP. This score (a good 4.38 out of 5) gave us a basis for comparison for when we were ready to test the VoIP calls over the network using Agilent�s VQT system.

As the show and therefore the game began, our team got off to a slow start, but that was partly because the show floor was very crowded, taking much of our players� time. However, a technician from Indigo Software was dedicated to SIP interoperability right from the start (and I personally thank Indigo for the commitment), so non-interoperability did not obtain too much of a lead. Throughout the day, configurations were being made and displayed on a large screen located above what was designated as the ConvergeNET portion of Indigo�s booth. It was this screen that drew some attention from passing attendees, and we often found ourselves explaining what we were doing to those who asked.

ConvergeNET has always been about awareness, not just for engineers but also for the consumer. We want everyone to know about the improvements being made in the quality of VoIP calls and show that different companies� equipment are becoming more and more interoperable. At this show, there was more attendee awareness than in the past, and we will always strive for continued awareness � part of the reason I�m writing this article.

In the ConvergeNET area, Indigo�s technician configured their SIP proxy server and user agent as well as SIP IP phones and other VoIP products from 3Com, Cisco, Mediatrix, Pingtel, and Siemens with the help from Nuera, Mitel, and TMC Labs. The representatives from Nuera also got their own gateway configured, and Mitel offered their IP phone into the mix. By the end of the first day (October 4th), calls from most of these products were ready to be made. We were cutting into non-interoperability�s lead.

Meanwhile, also by the end of the day, the configurations for the H.323 users on our team were in play. Anyuser.Com had their IP phones at bat and their gatekeeper from their home office waiting on deck. AltiGen had their gatekeeper and IP Phones (OEMed from Polycom) ready. Quintum had their gateway portion of the Tenor switch ready to register with the other gatekeepers and their gatekeeper portion waiting as a relief pitcher in case needed. Unidata waited in the wings with their IP phone. The stage was set for a comeback in the second half of the game, which took place the following day (October 5th).

In the bottom of the sixth inning, Nuera singled, Mitel bunted Nuera over to second, and Indigo singled Nuera home: All three companies were able to make calls to each other on the beginning of the second day. For example, Nuera made a call through Indigo�s SIP proxy to Mitel�s IP phone. Shortly afterwards, we further closed the gap by successfully connecting with 3Com, Cisco, and Siemen�s SIP phones. As a matter of fact, we made calls using every scenario possible with these companies� equipment. We even were able to call one phone to another, place that call on hold, and then dial out and connect to a different SIP phone. For example, we called from Nuera�s gateway to 3Com�s phone through Indigo�s proxy and then flash hooked so that we could dial out to Cisco�s phone. This was as close as we got to conferencing calls among all different vendors, but it is a significant achievement nonetheless.

Late in the game, we did also try to configure Mediatrix equipment and the Pingtel IP phone. Unfortunately, we were unable to successfully configure the Mediatrix gateway before the show ended and could not contact Pingtel in time to discover a password we needed to reconfigure the unit. However, most of the other SIP equipment we used has proven interoperability with the Pingtel phone already. Also, TMC Labs is planning to obtain Mediatrix�s IP Communication Server and 1104 products and put them through the ringer in an upcoming issue of Internet Telephony� magazine. We expect the equipment to perform admirably, but will let you know if it doesn�t.

I personally listened and spoke on many of the calls that took place, and most were of good quality, as if we were using the PSTN. On some calls made involving the Mitel IP phone, the conversation was more jittery as if muffled like talking on a wireless phone, but that was more noticeable because of the high quality of other VoIP calls, which easily surpassed that of most wireless calls. We would prove the high sound quality later when Agilent brought their VQT into the game.

Maybe I�m a little bit more hesitant about wireless connections, but that didn�t stop Quintum from hopping off AnyUser.Com�s H.323 gatekeeper and placing a call to both a regular analog phone and a wireless phone� and I must say, the quality wasn�t bad. AnyUser.Com also called with their IP phone through AltiGen�s gatekeeper. Unidata also registered with all of the gatekeepers (AltiGen�s, Anyuser.Com�s, and Quintum�s) and connected to various endpoints, whether it was through the gateway from Quintum or the IP phones. While all of these companies did interoperate with each other, they were unable to communicate from gatekeeper to gatekeeper before the show ended. However, true to the commitment to ConvergeNET, these companies plan to continue to attempt interoperability between each other, including gatekeeper-to-gatekeeper and other demonstrations.

It was the bottom of the ninth with two outs. With a tie score, but extra innings loom. Nuera is on third, and Agilent comes to the plate. Agilent is there to test as many of the IP calls as possible in the limited time we had left of the show. We decided to test calls from and to Nuera�s gateway, which had an analog connection so gave us a truer measure of delay, PSQM, and PAMS scores, to and from 3Com, Cisco, Mitel, and Siemens SIP phones. 

The biggest discrepancies were in the PSQM scores. We did attempt to test Cisco�s IP phone for PSQM scores, but were unable to obtain a reliable score, mainly because of how the phone sat. A ground loop occurred when testing the phone, causing inconsistencies in the results. This is a known issue with testing Cisco�s IP phone with Agilent�s VQT. In addition, we found mechanical clicks when testing from Nuera�s gateway to Mitel�s SIP phone, causing the mediocre 2.53 PSQM score. Without the clicks (which may not be the fault of either the SIP phone or the gateway), that score would have been much lower. I also want to point out that these tests are not based on the same measures as done in past Agilent testing (such as with the Agilent review in the May issue of Internet Telephony). For example, 3Com�s excellent scores would be more than a point higher using the older flat-rate measurement, which is still actually very good when using that rate anyway.

For variation, we measured for PAMS instead of PSQM scores when testing Siemens IP phone. When connecting from Nuera�s gateway to Siemens IP phone, the scores indicated some dynamic delay and packet loss, although the quality of the calls was still clear when actually listening in on the calls. We feel that the delay during these calls was due to a big jitter buffer or possibly a slow processor within Siemen�s phone.

Due in part to the reasons detailed earlier, 3Com�s SIP phone tested most accurately and seemed to have the best overall performance among IP phones analyzed. Unfortunately, however, 3Com�s SIP phone has recently been discontinued. We were flabbergasted about that because of its overall good performance. Also notable is the MOS score, which measured over 4 for most runs. These are admirable scores and are significant when comparing the network MOS score of 4.38, thereby showing consistently high quality calls.

With all of these tests in tow, there is no surprise to report that Agilent delivered the game-winning hit, ending the sixth ConvergeNET triumphantly. But while helpful, this game does not enter us into the playoffs. We have a while yet to go, but I foresee winning more games to reach our goal. I already envision more interoperability just because of SIP�s inclusion in Windows Messenger. Whatever one might say about Microsoft, anyone would agree about how this helps the interoperability cause. We are also beginning to see products that work or translate between both H.323 and SIP, helping our cause as well.

And now I shall make a proclamation � with continued effort, the Internet telephony industry will solve major interoperability issues by the end of 2003. By the time this article is in print, the baseball playoffs will be long over, but for us, the playoffs are still on the way, and during that time, we will continue to champion the case of complete interoperability. 

Adam Altman is a TMCLabs editor and the organizer for ConvergeNET at Internet Telephony Conference and EXPO�.

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