Bandwidth utilization in IPT

Unanswered Question
Feb 19th, 2008

How the bandwidth is utilized in IP Telephone?

I have this problem too.
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umarwaqqas Tue, 02/19/2008 - 08:56

We use G.711 within the region. Can't we use G.729 within the region and G.711 for other regions?

umarwaqqas Wed, 02/20/2008 - 02:45

If I am calling from one IPT to other IPT, which bandwidth will be used? WAN Bandwidth or bandwidth configured for IPT (Location)?

Case 1: -

2 IPTs in one room, going into one switch and then CM. Which Bandwidth is used by the Location field.

Case 2: -

One IPT is in one room and 2nd IPT is placed in another location over the WAN. Call Manager is handling the call and sends the request to router which is connected to WAN. Router Bandwidth is used or bandwidth configured for IPT in Location field?

Rajesh Revuru Wed, 02/20/2008 - 05:53


Please confirm the bandwidth settings for phones. You can find out from the device pool, if both phones are in the same device pool, and codec being used is G711, than approximately 80kbps is used per call


If the phones are in two different regions, and check the codec settings betweeen the regions, if it is G729 approximately 30kbps is used if it is G711 approximately 80kbps is used. If anyother codec is used you have to calculate using the bandwidth tool i posted in my earlier post.


thekingyoyo Sat, 03/01/2008 - 17:20


thank you very much rajeshrevuru for documentation.

i have another question: how much bandwith is used just for signalisation of a call.

thanks a lot

thekingyoyo Sun, 03/02/2008 - 08:35


thanks javalenc,

if i have 3 sites A,B and C

and i have 2 CM, (CM1:avaya) in site A and (CM2:call manager) in site B.

and i have gatway (avaya) in site C.

i have link betwwen site A and C and link between sites B and C

i have ipphones (avaya) in site C, who is controlled bye CM1, and i have ipphones (cisco) in site C who is controlled bye CM2.

and i have trunk with CM1 and CM2.

i want to know if ipphone in site C calls ipphone in site B, how much bandwidth is used in link between site A and C.

there is architecture in attachement file.

thank you

Jaime Valencia Sun, 03/02/2008 - 16:43

that depends on the region you have set between the elements as already explained in previous threads

go into your config and look the device pool from your devices, it contains the region they are configured to use.

then look for the other device pool and compare the region, if they're not in the same DP look into the region config, there you will see which codec will be used

we cannot tell you how much BW since that depends on the config you have

the BW will depend on the region to which the endpoints involved in the call are located in


Jaime Valencia Mon, 03/03/2008 - 10:36

then they should be using 24 kbps per call, that is covered in the link that was already posted in the before threads. have you had some time to go thru them?


thekingyoyo Mon, 03/03/2008 - 14:44


i know i read it, but i want to know bandwidth used just for indication of a call. the file posted explain the situation.

thankyou very much

Jaime Valencia Mon, 03/03/2008 - 14:53

OK, for the pure RTP should be 64 kbps for G711 and 8 kbps for G729.

Depending on the underlying technology usually the calculation is 80 kbps G711 and 24 kbps G729 including all layer 2 headers.

that are only the RTP packets with all layer 2 and 3 headers.

the signaling for the call is 150 bps and must be added per call



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