How is the queue limit calculated on the FlexWAN and Versatile Interface Processors (VIP)?
A. Assuming sufficient SRAM on the VIP or FlexWAN, the queue limit is calculated based on a maximum delay of 500ms with average packet size of 250 bytes. The following is an example of a class with one Mbps of bandwidth: Queue limit = 1000000 / (250 x 8 x 2) = 250 Smaller queue limits are assigned as the amount of available packet memory decreases and with a larger number of Virtual Circuits (VCS). In the following example, a PA-A3 is installed in a FlexWAN card for the Cisco 7600 Series and is supporting multiple subinterfaces with 2 MB Permanent Virtual Circuits (PVCs). The service policy is applied to each VC. class-map match-any XETRA-CLASS match access-group 104 class-map match-any SNA-CLASS match access-group 101 match access-group 102 match access-group 103 policy-map POLICY-2048Kbps class XETRA-CLASS bandwidth 320 class SNA-CLASS bandwidth 512 interface ATM6/0/0 no ip address no atm sonet ilmi-keepalive no ATM ilmi-keepalive ! interface ATM6/0/0.11 point-to-point mtu 1578 bandw
