snom, a Germany-based company, may not be the best
known player in the VoIP space, but they produce a
family of SIP and H.323 phones as well as SIP
proxy/registrars and SIP media servers that can compete
feature-for-feature against any of the “big boys.” When
you then factor price into the equation, snom is often a
much less expensive solution. The snom 100 and 200
phones are Linux-based, compatible with H.323/H.450 or
SIP protocol suites and contain Web browsers as well as
SMS functionality. snom utilizes and supports open
source and does not incorporate any special chips or
software in its phones. Thus, snom is not subject to
license fees, which add costs and are dependent on bug
fixing by other companies. We checked out both the snom
200 and the snom 100 and liked what we saw.
It was a strange concept at first, but we fell in
love with ability to actually “log onto” our desktop
VoIP phone using a standard browser. The snom phones’
integrated HTTP Web server makes configuration and
remote management easy. The company’s phones also
support LDAP and TAPI, which enables the ability to dial
from Microsoft Outlook or look up an employee in a
corporate directory. Other potential applications
include server-based voice recognition, presence, and
encryption.
The phones are compatible with VoIP gateways and
gatekeepers based on SIP and H.323/H.450. Features
include call list, deny list, call waiting, call hold,
call divert, conference call, transfer, redial, speed
dial, SMS send/receive, echo cancellation, phone book,
multiple ring tones, an HTTP Server, and a graphical
display with four soft keys.
The snom 200 features five programmable function keys
and two Ethernet ports. It features a dual line graphic
(2x24 character display), six LEDs, text display and key
pad, as well as an AC97-compliant audio subsystem.
Both the 100 and the 200 have a second Ethernet port
with VLAN support enables users to “daisy chain” the
phone with a PC. Both phone models feature multiple
language support, and very importantly they support
power over Ethernet via the IEEE 802.3af standard.
We tried to get the snom 100 and 200 to work with an
old beta version of Microsoft’s SIP-based RTC Server,
but weren’t successful — through no fault of the snom
phones. So instead we installed snom’s own SIP server
(snom 4S SIP Proxy/Registrar) and were able to
successfully register both the Snom 100 and 200 phones
with the SIP server. The 4S SIP Registrar Proxy, is
compatible with SIP phones from snom, Cisco, Pingtel,
and Siemens, as well as being interoperable with
Microsoft Messenger (which we successfully tested). The
proxy runs on Windows 2000 and XP, Linux, and
Solaris.
In addition, we also installed snom’s 4S SIP Media
Server, which enables media related features such as
voicemail, auto attendant, conferencing, and
announcements. (Keep an eye out for a full-fledged
review of the snom 4S SIP Media Server in a future
issue.)
Once the phones were registered, we were able to
successfully make calls from one phone to another as
well as conference in a third VoIP phone. The voice
quality was excellent with minimal latency. We used
Hammer’s Call Analyzer to determine its VoIP quality and
other parameters. First we measured the MOS score — a
voice quality measurement that approximates the ITU-T
Mean Opinion Score (MOS) metric by incorporating packet
loss, latency, and jitter. It scored an excellent 4.32
MOS score (0-5 range) as well as jitter that was 0. In
addition it had an R-Factor score of 94 ( 0-100 range,
0-bad, 100-best). The R-Factor score is determined using
stream metrics and the Telchemy
algorithm.
We should mention that STUN — which is incorporated
in all of snom’s SIP VoIP phones — enables you to easily
deploy SIP devices over most NAT routers. snom also
supports UPnP, which is another technology for resolving
VoIP across NAT issues.
Fairly unique to the snom VoIP phones is their
support for standard PC headsets since they use the same
jacks on the phones as you would see on a PC’s sound
card. We all know that a PC headset is an order of
magnitude less expensive than a phone headset, so this
is certainly a cost savings
advantage.
CONCLUSION
snom takes user
feedback to heart. For instance, they found that too
many users users would move their phones on their
desk and the A/C connector would come loose. They then
changed to an RJ-11 connector which was much sturdier
and less apt to become disconnected. We liked the
overall ergonomics of the phone, the use of open
standards, the built-in Web interface, and of course the
excellent voice quality. TMC Labs would not hesitate to
recommend the snom 100 and snom 200 VoIP phones.
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