Media Bypass consideration
We needed an integration with and behind the CCM 7.x.
Estimated for Enterprise Voice, 20% of the user should use Lync as their primary phone.
Audio Codec Bandwidth
|Audio codec||Scenarios||Audio payload bitrate (KBPS)||Bandwidth audio payload and IP header only (Kbps)||Bandwidth audio payload, IP header, UDP, RTP and SRTP (Kbps)||Bandwidth audio payload, IP header, UDP, RTP, SRTP and forward error correction (Kbps)|
|RTAudio Narrowband||Peer-to-peer, PSTN||11.8||27.8||39.8||51.6|
For video, the codec is always RTVideo.The bandwidth required depends on the resolution, quality, and frame rate. For each resolution, there are two interesting bit rates:
If we assume 20% EV user = 6,000 which make 10% concurrent call -> 600 throughout 3 Pool = 200 call concurrently.
So we need to consider the protocol used by Lync, the encryption and more. First with Cisco you cannot implement any encryption, so no TLS, which means you have medium security in this network. Cisco supports only codec g711ulaw.
Just compare the network call flow, if you have a mediation server in place, the client connect to the Mediation Server directly, which than trunk it and communicates with the Gateway, here CCM. If we have Media Bypass, the client directly connects to the CCM.
Lets do a very basic calculation:
200 call via RTAudio Narrowband (51.6kbps) to the consolidated Pool are: 10320kbps
200 call via g711ulaw (156kbps) with in the network to the CCM are: 31200kbps
If i would even calculate this with more concurrent calls, this more dramatically impacting the network.
Say we have 900 concurrent calls, which btw would require already 2 physical, or 5 virtual Mediation Server ;)
900 call via RTAudio to the consolidated Pool are: 46440kbps
- Ferrari electronics AG
- If you have a centralized topology without WAN links to branch sites, you can enable global media bypass, because fine-grained control is unnecessary.
- If you have a distributed topology consisting of one or more network regions and their affiliated branch sites, determine the following:
Author: Thomas Pött Managing Consultant Microsoft UC