Throughput Measurement - Cisco GRS Configuration Manual

Implementing Carrier Grade NAT on Cisco IOS XR Software
Ensure that you do not add more than 8 address pools as it might result in verification errors, thereby
Note
leading to the rejection of the configuration.
Some of the considerations regarding the configuration of multiple public address pools are as follows:
• The outside VRF and outside ServiceApp remain the same for different pools of addresses for a given
• The maximum size of the public address pool is 65536 addresses per CGN instance.
• The minimum size of the public address pool is 64 addresses.
• When a particular address pool is deleted, the associated translations are also deleted.
Reduction of the Minimum Size of Bulk Allocation
The minimum size of bulk allocation has been reduced to 8. This size can be specified by using the
bulk-port-alloc size command.
Configuration of Port Limit per VRF
For NAT44, you can configure different port limits for different inside-VRF instances. The port limit specified
per VRF overrides the port limit value specified globally. But if the port limit per VRF is not specified, then
the global port limit is applied. This configuration is supported for CGSE as well as CGSE-PLUS.
If the port limit is reduced, CGSE or CGSE-PLUS card will not terminate any translation. But no new
translations are created until the usage by the subscribers for that VRF falls below the port limit.
Configuration of Same Public Address Pool across Different NAT instances
A public address pool can be reused by different instances of NAT. But the address pool can be reused only
by different CGN instances on different service cards. The syslog gives details on the CGN instances and the
address pool that is being reused.
Two or more different instances of CGN can act as active-standby in an N:1 redundancy. In such configurations,
two CGSE cards can be in active mode with different address pools. A third CGSE card can act a common
standby for both of them. In this case, it makes easy if the third CGSE card is allowed to reuse the address
pools used on the other 2 CGSE cards.

Throughput Measurement

The service card, like CGSE, has smaller throughput compared to the other cards in the platform. Therefore
it drops packets at the service application interface if the traffic diverted to it is more than it can handle. Hence
it becomes very important to measure the throughput for a service card. From this release onwards, the
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inside VRF.
If the outside VRF and the outside ServiceApp are changed, then there are chances that
Note
a subscriber packet is routed onto different outside VRFs and different ServiceApps at
various times. Hence if you try to configure different address pools with different outside
VRF and different ServiceApps, the configuration is rejected.
Cisco IOS XR Carrier Grade NAT Configuration Guide for the Cisco CRS Router, Release 5.2.x
Throughput Measurement
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