Enabling Fragmentation - Patton electronics SmartNode Series Software Configuration Manual

SmartWare Software Configuration Guide

Enabling fragmentation

SmartWare supports FRF.12 interface and end-to-end fragmentation of large IP packets to reduce the delay
imposed on voice packets on slow links (less than 512 kps). As opposed to IP fragmentation (also supported by
SmartWare) Frame Relay fragmentation is transparent to the IP layer thus leaving IP packets unchanged which
may be important for IP based applications susceptible to IP fragmentation.
This procedure desribes how to enable Frame Relay fragmentation
Mode: Frame Relay
Step Command
1 node (cfg)#port serial slot port
2 node (prt-ser)[ 0/0 ]#framerelay
3 node (frm-rel)[ 0/0 ]#use profile
service-policy name out
4 node (frm-rel)[ 0/0 ]#fragment size Define the maximum size (in Bytes) of the Frame Relay pay-
5 node (frm-rel)[ 0/0 ]#pvc dlci
6 node (pvc)[ dlci ]#fragment size
Note For proper functioning do not specify a scheduler mode (burst-shaper, burst-
wfq, shaper, wfq) for the frame relay service policy profile. Also do not use
the frame relay service policy profile on IP layer but rather on frame relay
layer (mode framerelay). Make sure voice traffic is being given priority over
data (command 'source class local-voice priority').
Note FRF.12 end-to-end fragmentation and FRF.12 interface fragmentation are
incompatible. Thus make sure that both ends of a Frame Relay link run the
same fragmentation mode.
Note When running data and voice over a Frame Relay link it is advisable to only
configure fragmentation for the PVC that carries data traffic. This way frag-
mentation protocol overhead and fragmentation processing overhead is only
spent for data traffic and voice packets (whose length should be smaller than
the fragmentation length) do not consume processing power and protocol
overhead for fragmentation.
Serial port configuration task list
Selects the serial interface on slot and port.
Enter Frame Relay configuration mode.
Use the previously defined service policy profile on Frame
Relay layer (and not on IP interface level) in outward direc-
tion. For other profile settings refer to the software configura-
tion guide.
load (excluding Frame Relay header and trailer overhead)
for all PVCs (FRF.12 end-to-end fragmentation).
See also table below
Enters the PVC configuration mode by assigning a DLCI num-
ber to be used on the specified virtual circuit.
Define the maximum size (in Bytes) of the Frame Relay pay-
load (excluding Frame Relay header and trailer overhead)
for this PVC only (FRF.12 interface fragmentation).
See also table below
14 • Serial port configuration
Purpose
167