Catalyst 6000 DSP Resources
Function Capability
PSTN gateway WS-6608-T1 module:
24 calls per DS1 port
192 calls per module
WS-6608-E1:
30 calls per DS1 port
240 calls per module
Conferencing G.711 or G.723:
32 conferencing participants per physical port
Maximum conference size of six participants
256 conference participants per module
G.729:
24 conferencing participants per physical port
Maximum conference size of six participants
192 conference participants per module
MTP transcoding G.723 to G.711:
31 MTP transcoding sessions per physical port
248 sessions per module
G.729 to G.711:
24 MTP transcoding sessions per physical port
192 sessions per module
The 8-port T1/E1 Voice and Services module performs 24 transcoding sessions
per port when translating from G.729 to G.711. It does 31 sessions per port
for G.723 to G.711. So the 8-port module can scale to 192 or 248 sessions per
module depending on the LBR CODEC be utilized. Besides the higher density,
another difference between the Catalyst 6000 solution and the 4000 is that the
Catalyst 6000 is able to perform a mix of transcoding and conferencing within
the same DSP.You may wonder why this is important—as an example, if we have
a four-user conference call with two users crossing an IP WAN configured for a
LBR, the Catalyst 4000 would use one DSP for each user crossing the IP WAN
for converting their call to G.711, and four DSPs to convert the G.711 streams
into a time division multiplexing (TDM) stream to be summarized, and finally
four DSPs to mix the callers together, for a total of ten DSP resources. However,
the Catalyst 6000 will use four DSP resources to transcode and conference all the
callers into a single call.
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178 Chapter 6 • DSPs Explained
Each port on WS-6608-T1/E1 is configured with an IP address in order to
configure it as a PSTN gateway, conferencing, or transcoding resource in Cisco
CallManager.The address can be a static assigned address, or via DHCP. In addition
to the static IP address, a TFTP server must be configured since the configuration
is downloaded from a TFTP server.
NOTE
When designing conferencing services utilizing the Catalyst 6000, keep in
mind that the conferencing service does not span ports. This means that
any given conference cannot use resources from another port. Therefore,
a conference cannot support more participants than any given port will.