Posted by: Mudassir Ali | August 24, 2010

Per Call Bandwidth Consumption

Reference: http://ciscovoiceguru.com/470/useful-bandwidth-values/

Per Call Bandwidth Consumption

CUCM Locations-Based CAC Bandwidth Values
You can find this information in CUCM Admin > System > Locations > Add Location > Help > About This Page

  • G.711 call uses 80 kbps
  • G.722 call uses 80 kbps
  • G.723 call uses 24 kbps
  • G.728 call uses 16 kbps
  • G.729 call uses 24 kbps
  • GSM call uses 29 kbps
  • Wideband call uses 272 kbps

Gatekeeper-Based CAC Bandwidth Values
A “debug h225 asn1” will reveal “bandWidth 1280” in the ARQ. Note well, H225 debugs tack a 0 (zero) on the end of your values. Therefore, 128 kbps (G.711) will show 1280 and 16 kbps (G.729) will show 160.

  • G.711 call uses 128 kbps
  • G.729 call uses 16 kbps

QoS Bandwidth Values
Best document is the QoS SRND, page 33.
[L2 (G.729 = 20 kbps; G.711 = 80 kbps) + L3] * 8 * 50 = Value per call

  • 802.1Q Ethernet adds (up to) 32 bytes of Layer 2 overhead.
  • Point-to-point protocol (PPP) adds 12 bytes of Layer 2 overhead.
  • Multilink PPP (MLP) adds 13 bytes of Layer 2 overhead.
  • Frame Relay adds 4 bytes of Layer 2 overhead; Frame Relay with FRF.12 adds 8 bytes.

RSVP Bandwidth Values
A “debug ip rsvp messages” will show the worst-case scenario bandwidth value used. Look for “start requesting XX kbps” in the output.

The ip rsvp bandwidth value should be equal to (x-1 calls at normal scenario + 1 call at worst case scenario). For example, two G.729 calls would be calculated as 24 + 40 = 64 kbps. In the example below, I have configured RSVP for one G.729 calls (1-1 calls at normal scenario + 1 call at worst-case scenario of 40 kbps)

  • G.711 call uses 96 kbps as a 10 ms worst-case scenario.
  • G.729 call uses 40 kbps as a 10 ms worst-case scenario.

 

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