From: simon hart (simon@harttel.com)
Date: Tue Nov 01 2005 - 13:03:18 GMT-3
Dave,
At the default of 53 bytes there is still the possibility of voice packets
being fragmented. There are many variables as to what size the voice packet
will be, for example codec used (G.729 etc), sampling rate, whether cRTP is
being used. So your voice packet could be larger than 53 bytes and thus get
fragmented.
With respect to priority queueing, when you enter the frame fragment command
the interface changes to the dual fifo paradigm. Small (unfragmented)
packets get delivered to a high priority queue and fragmented packets get
delivered to a low priority queue. Unfragmented packets can be anyhing
below the fragment size and not just voice packets. If you wish to make
sure that 'only' voice packets go to the high priority queue, then use the
following command
ip rtp priority (rtp port range)
This will then deliver both LMI and voice packets to the high priority
queue.
The following link provides further information
http://www.cisco.com/en/US/tech/tk543/tk544/technologies_tech_note09186a0080
0a4754.shtml
HTH
Simon
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Schulz, Dave
Sent: 31 October 2005 22:05
To: ccielab@groupstudy.com
Subject: Frame-Relay fragmentation
I was working through the doc CD, where it stated something about the
FRF.12 inherently allows all voice traffic to pass-through unfragmented,
while fragmenting the data packets to the specific length. So, can I
assume that if a lab states to fragment all packets above 53 bytes (the
default), and allow voice to be unfragmented....then you may simply
configure "frame-relay fragment" command under the specific frame
map-class or interface, along with the frame-relay traffic-shaping
interface command?
I almost want to believe that priority queuing is needed, but am
confused on which way to go here (sometimes we make things more
complicated then they really are). Thoughts?
Dave Schulz,
Email: dschulz@dpsciences.com <mailto:dschulz@dpsciences.com >
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