Cisco 3825 - Manual (Page 255)

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Cisco 3825 Mobile Wireless Edge Router Software Configuration Guide
OL-15667-03
Appendix A Cisco 3825 Mobile Wireless Edge Router RAN-O Command Reference
umts-iub backhaul-timer
umts-iub backhaul-timer
To determine how often backhaul packets are sent for UMTS, use the umts-iub backhaul-timer
Interface configuration command. This option is commonly used for High Speed Downlink Data Packet
Access (HSDPA) offload environments. HSDPA traffic requires much more bandwidth than
voice/signaling traffic on UMTS. Customers can offload the HSDPA traffic to an alternate backhaul
media, such as metro-Ethernet while still maintaining low latency traffic (voice/signaling) on the
existing T1/E1s. By configuring a separate UMTS peer for the HSPDA interface(s) and a timer value in
the 3 ms to 8 ms range, customers can reduce CPU utilization on the Cisco 3825 router and save backhaul
costs by sending HSDPA across the lower cost metro-Ethernet.
Note The value should be carefully selected. Typically, it should not exceed 2 ms when the backhaul is T1/E1
MLPPP. However for alternate backhaul Frame Forwarding (FF) or Gigabit Ethernet (GE), this value can
be selected at a greater value to reduce the CPU load on the platform. Depending on the load the UMTS
interface and timer selected, the UMTS payload could exceed the Maximum Transmission Unit (MTU).
In this case, the backhaul packets will be sent when they reach the backhaul MTU (for non-MLPPP
backhauls). A maximum MTU of 450 bytes is used for MLPPP backhauls.
umts-iub backhaul-timer ? [1-8] timer value(in ms)
Syntax Description This command has no arguments or keywords.
Defaults Timer value of 1 ms.
Command Modes Interface configuration
Command History
Examples The following example shows how to determine how often the backhaul packets are sent for UMTS:
Router(config)# interface a0/3/0
Router(config-if) umts-iub backhaul-timer ?
<1-8> timer value(in msec)
Router(config-if)#
Release Modification
12.4(4)MR This command was introduced.