Inalp Networks SmartWare Release 2.10, Руководство по настройке программного обеспечения

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Serial Port Configuration 137
Software Configuration Guide Release 2.10, Revision 1.00
G.729 20 62
Step 3 node (frm-rel)[ 0/0 ]#use profile service-policy
name out
Use the previously defined service policy
profile on Frame Relay layer (and not on
IP interface level) in outward direction.
For other profile settings refer to the
software configuration guide.
Step 4 node (frm-rel)[ 0/0 ]#fragment size
Define the maximum size (in Bytes) of
the Frame Relay payload (excluding
Frame Relay header and trailer
overhead) for all PVCs (FRF.12 end-to-
end fragmentation).
See also table below
Step 5 node (frm-rel)[ 0/0 ]#pvc dlci Enters the PVC configuration mode by
assigning a DLCI number to be used on
the specified virtual circuit.
Step 6 node (pvc)[ dlci ]#fragment size
Define the maximum size (in Bytes) of
the Frame Relay payload (excluding
Frame Relay header and trailer
overhead) for this PVC only (FRF.12
interface fragmentation).
See also table below
N.B.: 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').
N.B.: 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.
N.B.: 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 fragmentation 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.
The purpose of end-to-end FRF.12 fragmentation is to support real-time and non-real-time data
packets on lower-speed links without causing excessive delay to the real-time data. The FRF.12
Implementation Agreement defines FRF.12 fragmentation. This standard was developed to allow
long data frames to be fragmented into smaller pieces (fragments) and interleaved with real-time
frames. In this way, real-time and non-real-time data frames can be carried together on lower-speed
links without causing excessive delay to the real-time traffic. End-to-end FRF.12 fragmentation is
recommended for use on permanent virtual circuits (PVCs) that share links with other PVCs that are
transporting voice and on PVCs transporting Voice over IP (VoIP).
The fragmentation size depends on the available bandwidth the chosen codec and its packet length:
• The less bandwidth available per call the smaller the fragment size has to be configured.
• The shorter the voice packets the smaller the fragment size can be configured.
• The smaller the fragment size the bigger the overhead for long data packets.
The following table shows the minimum fragment size depending on the configured codec and its
packet length without fragmenting the voice packets:
Codec Packet Period
[ms]
Fragment Size at least
[Bytes]
G.729 10 52