Cisco WS-X4604-GWY - VoIP Gateway Especificaciones descargar pdf (Pagina 160)

Chapter 6 Multisite WAN with Distributed Call Processing

Cisco CallManager Cluster Considerations

6-30

Cisco IP Telephony Network Design Guide

78-11103-03

Cisco CallManager Cluster Considerations

The following design considerations apply for Cisco CallManager clusters in a

distributed call processing environment using Cisco CallManager Release 3.0:

• Each Cisco CallManager cluster can support 10,000 users.

• No more than 2500 users can be registered on any given Cisco CallManager,

even under failure conditions.

• Only a single Cisco CallManager within a cluster registers with the

Cisco IOS gatekeeper at one time.

DSP Resource Provisioning for Transcoding and

Conferencing

This section briefly considers DSP resources in distributed call processing

environments. In a multisite WAN with distributed call processing, each site is

required to have DSP resources for conferencing and for transcoding across the

IP WAN. Conferencing and transcoding services are enabled by the Media

Termination Point (MTP) application.

The main purpose of transcoding DSP resources is to perform conversion between

different codec types in a Real-time Transport Protocol (RTP) stream in the event

of a codec mismatch. For example, a compressed G.729 media RTP stream across

the IP WAN might need to terminate on a device that supports only G.711. The

transcoding DSP resource would terminate the G.729 media stream and convert it

to G.711. This allows the media stream to remain compressed across the WAN.

Figure 6-17 depicts the function of DSP resources across the IP WAN, as listed in

the following steps:

Step 1 Caller 555-1212 in region B dials voice mail in region A.

Step 2 Cisco CallManager B sees that the destination is region A, LBR codec.

Step 3 Cisco CallManager A sees an LBR incoming call for a G.711-only device.

Step 4 The media stream is directed to the terminating side DSP farm.

1 2 ... 155 156 157 158 159 160 161 162 163 164 165 ... 261 262

Sin comentarios

Cisco WS-X4604-GWY - VoIP Gateway Especificaciones Pagina 160