DIMENSIONING - LIMITS CALL SERVER : VOICE ON IP
Ed. 046/8 Réf. 3EH 21000 BSAA
Medium configuration for mixed telephony + H.323 gateway
- 1 Operator station (non-IP)
- 5 IP Enabler stations
- 40 conventional Reflexes stations
- 4 T0 accesses
- 5 VoIP network accesses
A = 5; B = (8+5) - 4 + 0 = 9.
- The number of DSP channels needed for IP telephony is: Min(5, 9) = 5.
- The H.323 gateway requires 5 additional DSP channels.
The mean number of DSPs needed for this configuration is 10 (increased to 16).
Bandwidth
In an H.323 gateway configuration, a bandwidth can be associated with each ARS table entry to a
remote H.323 gateway.
Number of DSPs depending on communication type:
- IP Phone - IP Phone: 0 DSPs
- PC - PC: 0 DSPs
- PC with internal H323 gateway - PC with internal H323 gateway: 1 DSPs
- IP Phone in conference: 1 DSPs
- IP Phone or PIMphony IP - Reflexes station or analog/ISDN network: 1 DSPs
- IP Phone or PIMphony IP - PC H323 or H323gateway (IP trunk): 2 DSPs
The following table indicates the potential number of simultaneous communications depending on the
bandwidth reserved for Voice over IP calls:
Data rate (bandwidth) Number of simultaneous com-
munications possible
CODEC used
55.6 Kbps (or less) 1 G.723.1/G729a
64 Kbps 2 G.723.1/G729a
128 Kbps 5 G.723.1/G729a
256 Kbps 10 G.723.1/G729a
512 Kbps 20 G.723.1/G729a
≥ 1024 Kbps Depends on the number of IP
trunks
G.723.1/G729a