Cisco Cisco Expressway Maintenance Manual
About subzones
The Local Zone is made up of subzones. Subzones are used to control the bandwidth used by various parts
of your network.
of your network.
Three special subzones — the Default Subzone, the Traversal Subzone and the Cluster Subzone (only
applies if the Expressway is in a cluster) — are automatically created and cannot be deleted.
applies if the Expressway is in a cluster) — are automatically created and cannot be deleted.
Note that the Traversal Subzone is the only configurable subzone.
Default links between subzones
The Expressway is shipped with the Default Subzone and Traversal Subzone (and Default Zone) already
created, and with links between them. If the Expressway is added to a cluster then default links to the
Cluster Subzone are also established automatically. You can delete or amend these
created, and with links between them. If the Expressway is added to a cluster then default links to the
Cluster Subzone are also established automatically. You can delete or amend these
if you need
to model restrictions of your network.
About the Traversal Subzone
The Traversal Subzone is a conceptual subzone. Its sole purpose is to control the bandwidth used by
.
The
Traversal Subzone
page (
Configuration > Traversal Subzone
) allows you to place bandwidth
restrictions on calls being handled by the Traversal Subzone and to configure the range of ports used for the
media in traversal calls.
media in traversal calls.
Configuring bandwidth limitations
All traversal calls pass through the Traversal Subzone, so by applying bandwidth limitations to the Traversal
Subzone you can control how much processing of media the Expressway will perform at any one time. These
limitations can be applied on a total concurrent usage basis, and on a per-call basis.
Subzone you can control how much processing of media the Expressway will perform at any one time. These
limitations can be applied on a total concurrent usage basis, and on a per-call basis.
for more details.
Configuring the Traversal Subzone ports
You can configure the range of ports used for the media in traversal calls. A single traversal call can consist
of up to 5 types of media (audio, video, far end camera control, dual streams and BFCP) and each type of
media may require a pair of ports – for example, audio and video each require one port for RTP, and one for
RTCP. Separate pairs of ports are required for the inbound and outbound portions of a call. A single traversal
call can therefore take up to 20 ports; if the B2BUA is invoked this increases to 40 ports (or even more if extra
media lines are required) as the call is routed through the B2BUA hosted on the Expressway.
of up to 5 types of media (audio, video, far end camera control, dual streams and BFCP) and each type of
media may require a pair of ports – for example, audio and video each require one port for RTP, and one for
RTCP. Separate pairs of ports are required for the inbound and outbound portions of a call. A single traversal
call can therefore take up to 20 ports; if the B2BUA is invoked this increases to 40 ports (or even more if extra
media lines are required) as the call is routed through the B2BUA hosted on the Expressway.
The default media traversal port range is 36000 to 59999, and is set on the Expressway-C at
Configuration
> Traversal Subzone
. In Large Expressway systems the first 12 ports in the range – 36000 to 36011 by
default – are always reserved for multiplexed traffic. The Expressway-E listens on these ports. You cannot
configure a distinct range of demultiplex listening ports on Large systems: they always use the first 6 pairs in
the media port range. On Small/Medium systems you can explicitly specify which 2 ports listen for
multiplexed RTP/RTCP traffic, on the Expressway-E (
configure a distinct range of demultiplex listening ports on Large systems: they always use the first 6 pairs in
the media port range. On Small/Medium systems you can explicitly specify which 2 ports listen for
multiplexed RTP/RTCP traffic, on the Expressway-E (
Configuration > Traversal > Ports
). If you choose
not to configure a particular pair of ports (Use configured demultiplexing ports = No), then the
Expressway-E will listen on the first pair of ports in the media traversal port range (36000 and 36001 by
default). The port range can be changed to any values between 1024 and 65533. Ports are allocated from this
range in pairs, with the first port number of each pair being an even number. Therefore the range must start
with an even number and end with an odd number.
Expressway-E will listen on the first pair of ports in the media traversal port range (36000 and 36001 by
default). The port range can be changed to any values between 1024 and 65533. Ports are allocated from this
range in pairs, with the first port number of each pair being an even number. Therefore the range must start
with an even number and end with an odd number.
To configure the ports used for media in traversal calls, go to
Configuration > Traversal Subzone
.
Cisco Expressway Administrator Guide (X8.2)
Page 174 of 378
Bandwidth control
About subzones