Thursday, December 18, 2008

FRTS versus MQC FRTS - Part II

Following on from part I i know introduce a further requirement to set the frame-relay discard eligibility bit on all non critical frames (non DSCP 5).

For consistency i apply this on R4 using traditional FRTS on R4 and then using MQC FRTS on R5.

R4

1) i create a new class DSCP5 matching the critical traffic
2) I create a policy-map FR_405 that only sets the de bit for the non-critical frames
3) Finally within the pre-existing frame-relay map-class RICH i reference the new policy-map.

class-map match-all DSCP5
match dscp cs5

policy-map FR_405
class DSCP5
class class-default
set fr-de

map-class frame-relay RICH
frame-relay cir 768000
frame-relay bc 7680
service-policy output FR_405
frame-relay fragment 960


For verification is use the 'show frame-relay pvc 405' command

R4#s frame-relay pvc 405

PVC Statistics for interface Serial2/0 (Frame Relay DTE)

DLCI = 405, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial2/0

input pkts 169 output pkts 175 in bytes 21260
out bytes 18308 dropped pkts 6 in pkts dropped 6
out pkts dropped 0 out bytes dropped 0
in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
out BECN pkts 0 in DE pkts 0 out DE pkts 30
out bcast pkts 112 out bcast bytes 13140
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
pvc create time 00:17:45, last time pvc status changed 00:16:05
service policy FR_405
Serial2/0: DLCI 405 -

Service-policy output: FR_405

Class-map: DSCP5 (match-all)
0 packets, 0 bytes
5 minute offered rate 0 bps
Match: access-group 100
0 packets, 0 bytes
5 minute rate 0 bps
Match: dscp cs5 (40)
0 packets, 0 bytes
5 minute rate 0 bps

Class-map: class-default (match-any)
30 packets, 3169 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: any
QoS Set
fr-de
Packets marked 30
Output queue size 0/max total 600/drops 0
fragment type end-to-end fragment size 960
cir 768000 bc 7680 be 0 limit 960 interval 10
mincir 384000 byte increment 960 BECN response no IF_CONG no
frags 175 bytes 18308 frags delayed 0 bytes delayed 0

shaping inactive
traffic shaping drops 0



On R5

As on R4 the first 2 steps are identical: i create a new class and policy map. I then reference the new policy map from within the pre-existing service-policy RICH. Nested service policies!!!:-)

class-map match-all DSCP5
match dscp cs5


policy-map FR_405
class DSCP5
class class-default
set fr-de

policy-map RICH
class class-default
shape average 768000 7680
service-policy FR_405



For verification i use the 'show policy-map int s2/0.54' command.

R5#s policy-map int s2/0.54

Serial2/0.54

Service-policy output: RICH

Class-map: class-default (match-any)
1 packets, 84 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: any
Traffic Shaping
Target/Average Byte Sustain Excess Interval Increment
Rate Limit bits/int bits/int (ms) (bytes)
768000/768000 1920 7680 7680 10 960

Adapt Queue Packets Bytes Packets Bytes Shaping
Active Depth Delayed Delayed Active
- 0 1 84 0 0 no

Service-policy : FR_405

Class-map: DSCP5 (match-all)
0 packets, 0 bytes
5 minute offered rate 0 bps
Match: dscp cs5 (40)

Class-map: class-default (match-any)
1 packets, 84 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: any
QoS Set
fr-de
Packets marked 3



Both methods achieve the same result!

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