Getting realistic about VoIP Interoperability is a good and necessary thing, IMO.
You tell it like it is, Jeff. Way to go. Thanks.
See associated stories below. The first concerns Jeff's and others' views on this subject, and the second concerns Bellcore's joining with the LVLT-led Technical Advisory Committee (TAC).
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ip telephony/ on to interoperability
November 27, 1998
Inter@ctive Week via NewsEdge Corporation : Jeff Pulver, guru of Internet Protocol telephony, believed just a few months ago that vendors would quickly get together and make their equipment interoperable on the basis of industry standards. Now, Pulver's pulling down a figurative banner proclaiming 1999 "the year of interoperability" and acknowledges it might not go back up before 2001.
Interoperability is a key issue for Internet Protocol (IP) telephony. Without it, networks are, at worst, like pre-Bell system phone companies that required users to have different instruments for all the providers that serviced the people they wanted to talk with. At best, incompatibility requires service providers to buy multimillion-dollar switches to exchange traffic with counterparts supplied by different vendors. With interoperability, Pulver says, the technology will share the benefits of, say, automated teller machines that accept the same cards globally.
Carriers -- especially huge telephone companies that could push IP telephony into prime time -- require interoperability before making substantial investments. They want negotiating leverage and flexibility in upgrading, which they can't have with a sole source and a proprietary technology, says Francois de Repentigny, senior product marketing manager at vendor Clarent Corp. (www.clarent.com).
This pressure, along with historical precedents favoring compatibility, has made pledges of interoperability obligatory. Vendors typically boast that their equipment is H.323-compliant, referring to an International Telecommunication Union standard devised for desktop videoconferencing and appropriated by IP telephony. H.323 is far from a complete standard for IP telephony services, however, and compliance in two networks by no means equates to plug-and-play. "Our boxes [from different vendors] don't talk to each other," says Ed Hirshman, senior manager at ITXC Corp., a service wholesaler.
There has been concrete progress toward interoperability this year. Pulver has 225 members in his 8-month-old IP Telephony Memorandum of Understanding Workgroup; 175 represent carriers. Vendors have made a series of agreements to achieve network compatibility; a recent one involves industry pioneer VocalTec Communications Ltd. and networking behemoth Cisco Systems Inc. (www.cisco.com).
A similar agreement between VocalTec and Lucent Technologies Inc. (www.lucent.com) produced a September interoperability demonstration and the promise to release Dec. 2 technical specifications to standards bodies and on the Internet. ITXC (www.itxc.com), which brokered the deal, says three other vendors got sneak previews of the documentation and plan to announce the same day their commitment to interoperability with one another, plus with VocalTec (www.vocaltec.com) and Lucent. Further, AT&T Corp. (www.att.com) is talking with other industry players after announcing last month it will sponsor research to promote interoperability. Many issues besides equipment and peering for call handoffs remain unresolved, says Oleh Danyluk, AT&T's IP telephony marketing director, including guaranteeing quality of service, billing and settlement, and enhanced services.
But the trend is not running as fast -- or even in a single direction -- as Pulver and others would like.
IP carrier Delta Three Inc. cast its lot with primary vendor Ericsson Inc. Both swear allegiance to interoperability, but ITXC's Hirshman suggests the companies are going down a misbegotten proprietary path.
"Eventually, there's not going to be a choice," he says. "The customer base for proprietary product will shrink to zero."
The point, Pulver and others say, is that it's much easier for vendors to pay lip service to interoperability than it is to set aside rivalries and the lure of short-term gain through proprietary technologies. But without complete compatibility, the nascent industry will face trouble.
"There are good, positive signs of life," Pulver says, "but I'm telling you, it [full interoperability] won't happen before mid-2000, 2001. I'm just being realistic."
<<Inter@ctive Week -- 11-23-98>>
[Copyright 1998, Ziff Wire]
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linking up internet, telephone networks
November 27, 1998
Inter@ctive Week via NewsEdge Corporation : An industry standard designed to let voice-over-Internet Protocol networks communicate with the regular phone network is gaining support.
Last week, Bell Communications Research Inc. joined with a technical advisory committee headed by Level 3 Communications Inc. to consolidate their disparate technologies and present a unified group of specifications, called the Media Gateway Control Protocol (MGCP), to the standards-setting Internet Engineering Task Force for review. A completed standard is expected to be ratified in early 1999.
The standard could drive down networking equipment prices and spur the voice- over-Internet Protocol market by making packet-based networks more scalable and flexible.
MGCP is a hybrid of Level 3's packet-based Internet Protocol Device Control (IPDC) spec and Bellcore's (www.bellcore.com) circuit-based Simple Gateway Control Protocol. Both de facto standards address similar functions, including the way network connections are controlled, devices are managed and networks are secured.
MGCP works with other network standards and technologies, such as the SS7 network that controls circuit- switched communications and the H.323 standard for sending voice and video over IP networks. Some experts suggested the H.323 protocol could be extended to support MGCP-like functions. "But that would be reinventing something that we've worked on very hard for a long time," said Isaac Elliot, senior director of voice network engineering at Level 3 (www.l3.com) and chairman of the technical committee that developed IPDC.
Under the new proposal, call-management software, known as media gateway controllers, can be set up at various points along circuit-switched and packet- switched networks to allow for a transparent communication exchange between the two net- works. The media controller software resides separately from media gateway devices, such as voice-over IP gateways, voice-over-Asynchronous Transfer Mode devices, cable modems, private branch exchanges and circuit switches.
MGCP's separation of call control software from multimedia devices lets service providers construct more flexible and scalable networks. For example, a service provider could sell mixed-media services off several media gateways -- in various parts of its network -- while storing and managing user information centrally in the network.
"You can deploy gateways, like voice-over-IP devices, all over the world and only have to deal with dozens rather than hundreds of media controllers, " Elliot said.
A Network Connection
The Media Gateway Control Protocol is designed to standardize the way phone networks talk to Internet Protocol networks. It is based on a combination of existing Bell Communications Research Inc. and Level 3 Communications Inc. specifications.
Bellcore's Simple Gateway Control Protocol: A simple language for call and connection control between network end points and media gateways, such as voice- over-Internet Protocol gateways.
Level 3 Communications' Internet Protocol Device Control (IPDC): A specification that creates flexible management of media gateway devices. The Media Gateway Control Protocol removes the signaling transport portion of IPDC to cut down on the combined standard's overhead.
<<Inter@ctive Week -- 11-23-98>> |
