Lync 2013 Bandwidth Guide

A common question that customers ask is "What is the minimum bandwidth required for a Lync Device to operate?" This is very difficult to say as there are many components that use varying amounts of bandwidth. I use the follow as a general guide:

Audio 11.8 - 223.6 Kbps
Typical Averages
Peer to Peer 29.3 or 39.8 Kbps (RTAudio Wideband vs RTAudio Narrowband)
Conferencing 25.5 or 46.1 Kbps (Siren vs G.722)
PSTN: 30.9 or 64.8 Kbps (RTAudio Narrowband vs G.711)

Video 15 – 4000 Kbps
Typical Averages
Peer to Peer 460 Kbps (H.264)
Conferencing: 270 Kbps video send/260 Kbps video receive (H.264 or RTVideo)

Control Signaling 5 – 15 Kbps

So take calls to the PSTN as an example – 64.8Kbps (max PSTN bandwidth) x 3600sec (1 hour total talk time per day) x 31days (over 1 month) / 1,048,576 (number of Kbps in 1 GB) =  6.9GB per month.

For further technical details see - http://technet.microsoft.com/en-us/library/jj688118.aspx