Microsoft Unified Communications shuns G.722 wideband

Microsoft launched its UC (Unified Communications)products this month with the intention of replacing the traditionalPBX.  But before it can get to a dominant market share position if itever gets there at all, itâ€™s going to have to interoperate withexisting telephony systems on the existing standards that are inplace.  Unfortunately for Microsoft, the current UC products will notbe able to interoperate with the most commonly implemented patent-freewideband codec G.722in existing high-end SIP phones.  This means Microsoftâ€™s UC phones willbe restricted to narrowband calling when it tries to dial wideband enabled IP phonesfrom Cisco, Polycom, Avaya, Snom, Linksys, Mitel, Grandstream all ofwhich use standardized G.722.  Microsoft UC phones will instead go itsown route and use its own proprietary wideband codec called RTAudio and a proprietary Polycom codec G.722.1 called â€œSirenâ€.
I had asked Microsoft about G.722 compatibility during WinHEC in Mayand I got an answer when I got back home after the show and I wasshocked to hear that it didnâ€™t support it.  I spoke with members of theUC product team to let them know of my disappointment and argued from apractical perspective why Microsoft should simply add the royalty freestandardized codec to their UC platform.  What I got in response washow none of Microsoftâ€™s customers were asking for G.722interoperability and how old and inferior the codec was.  I told themthat from my perspective as a former IT person, I would not be happywith this incompatibility and that itâ€™s unlikely that their customerswould even know to ask about such a thing.
I contacted Polycom after the initial Microsoft meeting to see iftheir â€œHD Voiceâ€ branded wideband IP phones would support G.722.1 sothat it could interoperate with the UC phones.  I turned out Polycomwideband â€œHD Voiceâ€ IP phones only supported G.722 and G.722.1 â€œSirenâ€is only used in Polycomâ€™s high definition video conferencing products. I then had a conference call in June with Polycom CTO (and cofounder)Jeff Rodman to discuss how the world of Video conferencing andtelephony donâ€™t interoperate at wideband.  Jeff Rodman explained thatthe phones not only have limited processing capability but limitedmemory.  While certain compression algorithms may be computationallyfeasible, they wonâ€™t necessarily fit in the memory space of standaloneIP Phones.  This may be the reason that G.722 - while not as effectivein compressing wideband audio at lower bitrates - is the only codecthat is universally supported.
Fancier codecs like RTAudio and G.722.1 which produce smallerstreams at the same quality level are more suited to high-end videoconferencing end points and general purpose computers that have morethan enough CPU and memory to handle the workload.  So while G.722.1and RTAudio may have better compression ratios with wideband audiostreams of 32kbps, it may be too complex for dedicated hard IP Phones. While G.722 produces a less compressed 48 to 64 kbps wideband stream,the difference isnâ€™t as big when you factor in the 18.8 kbps of IP/UDP/RDP header overhead on a TCP/IP network.  By the time header overhead is counted, weâ€™re really comparing 66.8 to 50.8 or at worst 82.8 versus 50.8.
So now that Microsoft has launched their Unified Communicationsproduct, I went back to Microsoft to ask for a status update. Unfortunately it was pretty much the same arguments I heard back in mayand here is the official reply Microsoft sent me last week.

Quote:

â€œFrom a customer perspective, we have not had anyrequests for adding this codec to our stack. Further, while the PolycomHD SIP phones support G.722, we havenâ€™t seen large installations usethis codec. From a technical perspective, 722 was first developed forISDN video conferencing â€“ itâ€™s quite old. As a result, it doesnâ€™tsupport the same level of resiliency to packet loss or use of bandwidthon the wire that more modern codecs like RTAudio provide. Itâ€™s criticalthat we provide our customers the best possible quality of experiencewith Office Communications Server 2007 and at this time we donâ€™t seeG.722 support as advancing that goal forward.â€

As I told Microsoft in person, I donâ€™t have a problem with advancedcodecs like RTAudio and G.722.1 but I do have a problem with lack ofinteroperability. At this point in time I think it would be fair tosay that G.722 enabled devices absolutely dwarf Microsoft UC devices. Interoperability shouldnâ€™t be something that you only do when a largeenough customer threatens to avoid Microsoftâ€™s UC products unless theymake their products interoperable. Furthermore, I doubt Microsoftactually took a poll of its customers or advertises the fact that theycanâ€™t do G.722 which is the only wideband codec support on all theother IP phones on the market.
Microsoft has made a lot of progress in recent years in the area ofopenness and I fear this is a regression to the old closed Microsoft. I actually have some high hopes for Microsoftâ€™s UC platform and Iespecially like the fact that you can set up your own web conferencingportal. Iâ€™ve deployed Microsoftâ€™s conferencing products all the wayfrom Exchange Conferencing Server to Microsoft Live CommunicationServer 2003. I still intend to fully evaluate the new OfficeCommunication Server 2007 but the lack of G.722 interoperability andthe UC teamâ€™s attitude towards this matter has soured things for meespecially when they admit itâ€™s trivial for them to add G.722compatibility. I think there is plenty of room for a product that canfree us from the tyranny of proprietary PBXs but only if the liberatoradopts open standards.