Call Admission Control Considerations
While designing the IPT network, you need to collect the traffic patterns to better engineer the traffic flows. The information listed in Table E-1.)For the CAC mechanism to function properly, the WAN topology should follow the hub-and-spoke model. Yes No | 3 | What type of CAC mechanism will be deployed? | CallManager locations CAC Gatekeeper CAC |
4 | If deploying gatekeeper CAC, how many CallManager clusters are interconnected via the gatekeeper? | Number of clusters______________________________ |
5 | What is the estimated number of calls per second (CPS) that the gatekeeper needs to process?This determines the gatekeeper hardware to be deployed. | CPS______________________________ |
6 | What is the number of gatekeepers required in the network and gatekeeper network design? (Identify the requirements for the directory gatekeeper.) | Number of Gatekeepers______________________________ |
7 | Which type of gatekeeper deployment will be used? | HSRP Cluster |
Table E-15 lists the on-net call requirements and call volumes from remote sites to central sites.Table E-15. CAC Bandwidth Values for WAN Links
No. | On-Net Call Path | On-Net Calls Allowed |
---|
1 | Central site Site 1 | Voice | G.729 G.711 G.723 Other _______Number of calls ___ |
| | Fax | |
| | | G.711 |
| | | Other _______ Number of calls ___ |
| | MoH | G.729 G.711 |
| | | Other _______ |
| | | Number of calls ___ |
| | RTP compression? | Yes No |
| | Does this site use location CAC or gatekeeper CAC? | Location CAC Gatekeeper CAC |
| | Total bandwidth that needs to be reserved for this site | |
| | | _______ kbps |
Notes/Comments
When you are sizing the WAN bandwidth and the CAC, you need to determine the number of calls that traverse the WAN links. You need to take into consideration the fax and MoH streams in addition to voice calls. The choice of codec for each type of call also has an effect on the total bandwidth required on the WAN links.