How much bandwidth does a 3Com phone take?

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fibroptikl

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I'm setting up a new router and creating some VPN's for some remote sales guys.

I'd like them to be able to use their phones (as they do now) but want to make sure that I have enough traffic on our end to make it work alright. (It's kind of spotty now)

Our phone system is a 3Com NBX 100.

The phones are 3Com NBX 3102 Phones.

Any of you guys have any idea on how much bandwidth a phone like this would need?
 
Are these voip phones?

The VOIP I've used have typically been 96k to 128k. It's not very high.
 
depends on the compression scheme


some are as low as 7kbps


i think the highest is 64


basically, not much
 
It depends on which protocol they use. G.711 uses 64kb/s while the crappier sounding G.711 uses about 11kb/s..
 
I use a few Cisco phones with SIP over my network and over 512kb ADSL (yes 0.5mb)

People can be totaly flooding the ADSL where pings are sky high and my SIP calls are flawless.

They take about 96Kb that about 12KB and always prioritise their packets. You could run a lot of these over ISDN or ever 56K if you had to, really fantastic.
 
Thanks guys.

Some router problems prevented me from putting the new firewall in so no testing the VPN's to see how I can get the things to route.
 
Depends on the codec being used. My guess is, G.711 which is 64kb/s however don't forget to add in TCP overhead so your looking at around 82kb per call.

G.729a is another well used codec which is 8kb/s with tcp overhead roughly 18kb/s.

I doubt the 3com NBX supports it, but if you want to look into it, iLBC is the way to go with low speed links. Its 15.2kb/s but handles packet loss, delay and jitter much much better. (Same codec that skype uses)

You might also want to look into the MOS score for each codec. G.711 is the industry standard and has the highest MOS scores. G729a and iLBC are very similar.
 
The first vendor I had used 96kb/sec. They are defunct now, and I forget the name...



Verge said:
depends on the compression scheme


some are as low as 7kbps


i think the highest is 64


basically, not much
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