Cisco Cisco Expressway 维护手册
Figure 10 Maximum port allocation for a media traversal call
In practice, you probably won't reach the maximum number of concurrent traversal calls, have them all routed through
the B2BUA, and have all the possible types of media in every call. However, we defined the default range to
accommodate this extreme case, and the Expressway raises an alarm if the total port requirement could exceed the
port range you specify.
the B2BUA, and have all the possible types of media in every call. However, we defined the default range to
accommodate this extreme case, and the Expressway raises an alarm if the total port requirement could exceed the
port range you specify.
What is the default range?
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 (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).
> 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 (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).
Applying Bandwidth Limitations to the Traversal Subzone
You can apply bandwidth limits to the Traversal Subzone as follows:
Limitation
Description
Total
Limits the maximum bandwidth available for all concurrent traversal calls.
Calls handled by...
The maximum bandwidth available to any individual traversal call.
For all the above limitations, the Bandwidth restriction setting has the following effect:
■
No bandwidth: no bandwidth is allocated and therefore no calls can be made.
■
Limited: limits are applied. You must also enter a value in the corresponding bandwidth (kbps) field.
■
Unlimited: no restrictions are applied to the amount of bandwidth being used.
If your bandwidth configuration is such that multiple types of bandwidth restrictions are placed on a call (for example,
if there are subzone bandwidth limits and pipe limits), the lowest limit will always apply to that call.
if there are subzone bandwidth limits and pipe limits), the lowest limit will always apply to that call.
Links and Pipes
Configuring Links
Links are configured between zones and the Traversal Subzone.
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Cisco Expressway Administrator Guide
Bandwidth Control