Branch Office
If you are in a central branch office and your needs are to have an integrated and
simplified solution, the Catalyst 4000 switch with the AGM is an excellent choice.
The Catalyst 4000 is a recommended solution for a branch office with connections
to the PSTN and possibly an IP WAN circuit to another office. For example, a
branch office that has 175 employees with 140 IP phones and PCs in turn requires
the ability to perform multiparticipant conferencing and transcoding.The
transcoding is a requirement because they have some users running Microsoft
NetMeeting with G.723 CODEC performing audio conferencing with IP phones.
The Catalyst 4006 with a CallManager can provide all the needs for this branch
office environment.The AGM running in IP telephony gateway mode will provide
the DSP resources to allow conferencing and transcoding. Figure 6.4 illustrates how
the Catalyst 4000 is the backbone of the IP telephony solution supplying PSTN,
www.syngress.com
Table 6.5 Continued
IOS Support VG200 2600 3620, 3640 3660
184 Chapter 6 • DSPs Explained
WAN, LAN connectivity, and DSP farm resources in this single box solution. 24
conference participants and 16 transcoding sessions can be supported per AGM
module.When planning and designing your AVVID network, which includes calculating
your DSP resources, you need to put adequate effort in the analysis of how
the telephony network will be utilized and where the need for transcoding lies.
Accurate estimates of the number of conferencing sessions need to be performed. If
undersized, you will not be providing the level of service necessary to have satisfied
users. If oversized, you may not be spending your investment dollars wisely.This
environment is conducive to the Catalyst 4000 AGM, since conferencing should be
completed with all participants running a G.711 CODEC and not requiring any
transcoding, which will use more DSP resources.