[SIPForum-discussion] calculate number of calls

[Karthik Ramiya]

Hi Chris,

      I can see only the layer 2 overhead 6 bytes and the layer 3 overhead which is of 40 bytes that is missing here.

6(Layer2 overhead) + 40(ip_udp_rtp_overhead) + 160(packet or sample size) = 206
206/ 160 * 64000 (g.711) = 82.4 kbps
768 / 82.4 = 9.32 no. of calls.

Hope this helps.

Cheers,
Karthik



________________________________
From: discussion-bounces at sipforum.org [discussion-bounces at sipforum.org] On Behalf Of Chris Anderson [chrisdotanderson at gmail.com]
Sent: Saturday, October 24, 2009 1:40 AM
To: discussion at sipforum.org
Subject: [SIPForum-discussion] calculate number of calls

hello all.  i hope this is the right place to post my first question.  i'm having a problem calculating the number of calls that can be made at one time.   any help would be helpful.

here are the attributes.
codec -g.711
wan bandwidth - 768Kbps
packet header - 6 bytes
payload - 160 bytes
crtp- no.
here is the formula i've been using.

packet header + crtp + payload = x
x / payload * bitrate = y
wan bandwidth / y = # of calls.
or
6 +(no crtp = 0) 0 + 160 = 166
166 / 160 * 64 (g.711) = 66.4
768 / 66.4 = 11.5
# of calls 11.5

i know thats the wrong answer, but i don't know where i'm going wrong.

any help would be great.   thanks in advance.

--
Thanks,

Chris Anderson

**************** CAUTION - Disclaimer *****************
This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely 
for the use of the addressee(s). If you are not the intended recipient, please 
notify the sender by e-mail and delete the original message. Further, you are not 
to copy, disclose, or distribute this e-mail or its contents to any other person and 
any such actions are unlawful. This e-mail may contain viruses. Infosys has taken 
every reasonable precaution to minimize this risk, but is not liable for any damage 
you may sustain as a result of any virus in this e-mail. You should carry out your 
own virus checks before opening the e-mail or attachment. Infosys reserves the 
right to monitor and review the content of all messages sent to or from this e-mail 
address. Messages sent to or from this e-mail address may be stored on the 
Infosys e-mail system.
***INFOSYS******** End of Disclaimer ********INFOSYS***