Cable Television Laboratories Inc.'s PacketCable task
force has crossed a key threshold on developing Internet-protocol specifications, just as
red flags popped up about the first in a scheduled batch of IP standards.
The good news is that PacketCable's
specifications-setting process will be buttressed by a royalty-free pool for
intellectual-property rights. The PacketCable IPR (intellectual-property-rights) pool
already boasts 18 signatories.
That move will help to reduce the uncertainties that
vendors may encounter in producing PacketCable products, said David Reed, vice president
for strategic assessment at CableLabs.
Notably, no one involved in PacketCable, including
CableLabs' member MSO companies, expects services like IP telephony to be technically
feasible until 2000.
But Reed acknowledged that some MSOs, such as Le Groupe
Videotron, will move ahead of formal standardization. Videotron has slated an IP-voice
rollout for late 1999.
"We don't want to hold up deployments until the
standards are completed," Reed said. "A lot of our service-company members will
move ahead, anticipating that they will be able to upgrade to be in compliance once the
standard is complete."
The 12 vendors that have signed on as authors of
specifications in the IPR pool are: Bell Communications Research (Bellcore), Broadcom
Corp., Cisco Systems Inc., Com21 Inc., 8X8 Inc., Motorola Inc., NetSpeak Corp., Nortel
(with Bay Networks Inc.), 3Com Corp., TransNexus LLC, VideoServer Inc. and VocalTec
Communications Ltd.
Others in the pool -- some of which might eventually opt to
become spec authors -- are Arris Interactive, Broadband Access Systems, Hybrid Networks
Inc., Phasecom Inc., Tellabs Operations Inc. and Vienna Systems Corp.
Other participants are anticipated, Reed said, adding that
corporate procedures for approving such actions take longer at some companies than others.
Lucent Technologies, for example, has been involved with the PacketCable initiative almost
from its inception, but it has not joined the IPR pool.
The first group of PacketCable specs, slated for release
next month, will focus on the interfaces that will allow IP telecommunications to be
provided over cable networks to "thin clients," Reed said. Thin clients are
devices, often built into cable modems, which will serve as the "gateways"
between customers' standard telephones and the IP-telephony data channel over cable.
Additional specifications, slated to be released in stages
through the first half of 1999, will include interfaces designed to exploit higher levels
of processing power in personal computers and other end-user client devices, Reed said.
To issue that first, thin-client spec, PacketCable and its
participants must decide on a key, controversial interface used to handle communications
between a centralized "call agent" and the individual client gateways.
Debate over this interface, which determines how a basic
call setup is handled, is tantamount to a "religious war" in PacketCable
circles, noted Karl May, vice president and general manager of broadband technology at
Nortel.
May and others said it was likely that PacketCable would
endorse SGCP (single-gateway control protocol) over the signaling procedures incorporated
within the H.323 Internet-telephony standard -- despite the wide-scale deployment of
systems based on H.323 by entities outside of the cable industry.
SGCP -- which was developed by Cisco and Bellcore as a key
part of their newly integrated IP-telecommunications solution -- is under study at the
Internet Engineering Task Force as a solution to carriers' needs for simple signaling
methods that don't require a lot of computation at the end points.
Meanwhile, H.323 proponents are strongly urging the
PacketCable group to endorse an option known as "H.323 Lite," in order to ensure
complete compatibility with the existing H.323 base worldwide, said David Sokolic,
marketing director at VocalTec, a leading supplier of gateways and gatekeepers under the
H.323 regime.
"With the ITU [International Telecommunications Union]
and other standards bodies pushing H.323, the cable industry would be doing itself a
disservice to adopt something radically different," Sokolic said.
Sokolic questioned whether other protocol techniques, like
SGCP, are simply disguised efforts by other vendors to stall for time while they catch up
with IP-telephony technologies or advance proprietary techniques.
But backers of SGCP said it is not meant to replace H.323
for many basic functions, such as translating calls between the PSTN (public switched
telephone network) and IP domains, or managing call-address files.
Nonetheless, SGCP is too cable-centric for some cable
interests. May noted that Nortel -- which he described as "neutral" on the SGCP
vs. H.323 Lite debate -- is supplying customers in the cable domain that are
"absolutely committed" to H.323, no matter which way PacketCable goes.
These include many customers overseas that already provide
IP-voice services through H.323 gateways. Many of those groups want to add local
cable-distribution components to their existing IP-telecommunications infrastructure, May
noted.
But there are U.S. cable interests that are firmly in the
H.323 camp, as well, he said.
One of those may be AT&T Corp. In a discussion of the
carrier's new IP-telephony agenda at a recent press conference, officials said new
research facilities devoted to fostering interoperability and new technology would be
committed to advancing H.323, including in areas touching on the call-setup domain where
SGCP resides.
