Snom Swears Its Strictly SIP

By eweek  |  Posted 2004-06-25

Snom Swears Its Strictly SIP

If youre willing to bet your business phone system on IP telephony, want to keep it in-house, and want to pay less than you would for Cisco Systems Call Manager or the IP PBXes of the traditional players, you might try a system from snom.

Snom, based in Berlin, with offices in Coppell, Texas, was early out of the gate with IP phones years ago, back when H.323 was still the reigning VOIP (voice over IP) protocol. Today, snom pledges particularly strict adherence to the latest Internet Engineering Task Force (IETF)-ratified SIP (Session Initiation Protocol) specifications. The company is so standards-compliant, in fact, that its phones will work with the Asterisk open-source Linux SIP server.

Voice quality sounded fine to me as I tested its voice mail features on the floor at Supercomm. Not a very meaningful test in a self-enclosed system on the show floor, I know, but not all phone systems achieve good quality on the show floor.

Snom also sells its own switching server, the snom 4S. Like any IP PBX, it internally digitizes and packetizes voice, routes it through the enterprise LAN and (if so configured) out a WAN. To convert voice traffic back out to the circuit-switched world of traditional phones, users hook it up to an Audiocodes Ltd. or Vegastream gateway, says Christian Stredicke, a manager at snom.

But if far-flung employees put snom phones (or other, strictly SIP phones) anywhere in the broadband universe, they have PBX-extension functionality from that desk. They also have the home offices dial tone to use to dial destinations in the home-office country. That means, in effect, that the Japanese correspondent using an Atlanta-based snom server can dial a local call in Atlanta. The call goes out through the Atlanta gateway, and it is charged as a local call.

The Web server built into the 4S allows users to pick up voice mail messages, set call-forwarding options and set up conferences, from any browser. The auto-attendant allows users to record multilevel menus of recorded information, accessible by prompts and touchtone. And, of course, the 4S runs the gamut of PBX functions: caller ID, speed dials, hold, transfer, call waiting, music-on-hold and call blocking.

Next Page: The 4s is good for the basic office but not for the call center.

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The 4S server software (more properly called a SIP Proxy/Registrar) runs $8,000 for a 500-user license and comes in Windows, Linux and Solaris versions. The phones range in price, LED size, and functionality, between $200 and $250. You also need the snom media server to run the voice mail, auto-attendant, music-on-hold and conferencing features.

You may also need the snom 4s NAT Filter server ($7,000 for the software), which enables calls to traverse NAT (network address translation) firewalls. The NAT filter uses new protocols, called ICE (Interactive Communications Establishment) and STUN (Simple Traversal of UDP through NAT) to find and use the shortest physical paths between media endpoints whenever possible.

The server supports call recording, such as you find in brokerage call centers, where proof of all verbal transactions must be kept. It also allows wiretapping, a feature that snom promotes to those considering employing the server on a service-provider basis (such as ISPs). As service providers, they must be able to give the FBI and other law-enforcement agencies unobservable access to calls.

Stredicke admits that for now, the SIP business phone system is fine for the basic office. SIPs specs alone dont cover some of the features needed for call centers, and those SIP-based systems that do support them may be presumed to have added proprietary extensions to the spec. One example of these features is agent coaching: A call center supervisor can listen in on service-rep calls and whisper advice into his ear, undetectable to the calling customer.

Check out eWEEK.coms VOIP & Telephony Center at for the latest news, views and analysis on voice over IP and telephony.

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