MQC-based Frame Relay Traffic Shaping

This is a "modern" way to configure FRTS, using MQC commands only to accomplish the task. With MQC approach, an unified interface has been introduced to configure all QoS settings, irrelevant of underlying technology.

In summary:

- Legacy command frame-relay traffic-shaping is incompatible with MQC-based FRTS (you can't mix them)
- Fancy queueing could not be used as a PVC-queueing strategy: CBWFQ is the only option available
- Per-VC CBWFQ is configured via hierarchical policy-maps configuration: Parent policy sets shaping values, while child policy implements CBWFQ
- You may apply policy-map per-interface (subinterface) or per-VC, using match fr-dlci under class-map submode

Example: Shape PVC to 384Kbps and provide LLQ treatment for voice bearer packets on PVC queue

class-map VOICE

 match ip dscp ef

!

class-map DATA

 match ip dscp cs1
!

! "Child" policy-map, used to implement CBWFQ

!
policy-map CBWFQ

 class VOICE

  priority 64

 class DATA

  bandwidth 128

 class class-default

  fair-queue
!

! "Parent" policy map, used for PVC shaping

!
policy-map SHAPE_384K

 class class-default

  shape average 384000

  shape adaptive 192000

  service-policy CBWFQ
interface Serial 0/0/0:0.1

 ip address 177.0.112.1 255.255.255.0

 service-policy output SHAPE_384K

 frame-relay interface-dlci 112

Verification: check out policy map settings

Rack1R1#show policy-map interface serial 0/0/0:0.1
 Serial0/0/0:0.1 
  Service-policy output: SHAPE_384K
    Class-map: class-default (match-any)

      1942 packets, 1590741 bytes

      5 minute offered rate 48000 bps, drop rate 0 bps

      Match: any

      Traffic Shaping

           Target/Average   Byte   Sustain   Excess    Interval  Increment

             Rate           Limit  bits/int  bits/int  (ms)      (bytes)

           384000/384000    2400   9600      9600      25        1200     
        Adapt  Queue     Packets   Bytes     Packets   Bytes     Shaping

        Active Depth                         Delayed   Delayed   Active

        -      0         1936      1581717   0         0         no
      Service-policy : CBWFQ
        Class-map: VOICE (match-all)

          0 packets, 0 bytes

          5 minute offered rate 0 bps, drop rate 0 bps

          Match: protocol rtp

          Match: ip dscp ef (46)

          Queueing

            Strict Priority

            Output Queue: Conversation 40

            Bandwidth 64 (kbps) Burst 1600 (Bytes)

            (pkts matched/bytes matched) 0/0

            (total drops/bytes drops) 0/0
        Class-map: DATA (match-all)

          0 packets, 0 bytes

          5 minute offered rate 0 bps, drop rate 0 bps

          Match: ip dscp cs1 (8)

          Queueing

            Output Queue: Conversation 41

            Bandwidth 128 (kbps) Max Threshold 64 (packets)

            (pkts matched/bytes matched) 0/0

        (depth/total drops/no-buffer drops) 0/0/0
        Class-map: class-default (match-any)

          1942 packets, 1590741 bytes

          5 minute offered rate 48000 bps, drop rate 0 bps

          Match: any

          Queueing

            Flow Based Fair Queueing

            Maximum Number of Hashed Queues 32

        (total queued/total drops/no-buffer drops) 0/0/0

The amount of bandwidth, available for allocation to CBWFQ classes, is taken from shape adaptive value. If the latter is not configured, shape average
value is used instead. Note, that as you configure bandwidth settings for classes, their values are not subtracted from remaining bandwidth. This is in contraty with
"classic" CBWFQ, applied to a physical interface (not subinterface or PVC)

Verification (with the example above):

Rack1R1#conf t

Enter configuration commands, one per line.  End with CNTL/Z.

Rack1R1(config)#policy-map CBWFQ

Rack1R1(config-pmap)#class class-default

Rack1R1(config-pmap-c)#no fair-queue

Rack1R1(config-pmap-c)#bandwidth 256

I/f  shape  class class-default requested bandwidth 256 (kbps), available only 192 (kbps)

Note that available bandwidth is set to shape adaptive value, even though we have priority configured under class VOICE and bandwidth
settings under class DATA

- You can't apply FRF.12 fragmentation with MQC commands - it should be applied at physical interface level. By doing so, FRF.12 is effectively enabled for all PVCs
- Physical interface queue could be set to any of WFQ/CQ/PQ or CBWFQ (not restricted to FIFO as with FRTS legacy) - though this is rarely needed

Example: Shape PVC DLCI 112 to 384Kpbs and enable FRF.12 fragmentation for all PVCs

class-map VOICE

 match ip dscp ef

!

class-map DATA

 match ip dscp cs1
!

! Match the specific DLCI

!

class-map DLCI_112

 match fr-dlci 112
!

! "Child" policy-map, used to implement CBWFQ

!
policy-map CBWFQ

 class VOICE

  priority 64

 class DATA

  bandwidth 128

 class class-default

  fair-queue
!

! "Parent" policy map, used for PVC shaping

!  With multiple classes, we can match different DLCIs

!  all at the same physical interface (where they belongs)

!
policy-map INTERFACE_POLICY

 class DLCI_112

  shape average 384000

  shape adaptive 192000

   service-policy CBWFQ
!

! Apply the parent policy map at physical interface level

! Also, configure FRF.12 "global" settings here

!
interface Serial 0/0/0:0

 service-policy output INTERFACE_POLICY

 frame-relay fragment 640 end-to-end

Verification:

Rack1R1#show policy-map interface serial 0/0/0:0
 Serial0/0/0:0 
  Service-policy output: INTERFACE_POLICY
    Class-map: DLCI_112 (match-all)

      1040 packets, 95287 bytes

      5 minute offered rate 0 bps, drop rate 0 bps

      Match: fr-dlci 112

      Traffic Shaping

           Target/Average   Byte   Sustain   Excess    Interval  Increment

             Rate           Limit  bits/int  bits/int  (ms)      (bytes)

           384000/384000    2400   9600      9600      25        1200     
        Adapt  Queue     Packets   Bytes     Packets   Bytes     Shaping

        Active Depth                         Delayed   Delayed   Active

        -      0         1040      95287     4         1373      no
      Service-policy : CBWFQ
        Class-map: VOICE (match-all)

          0 packets, 0 bytes

          5 minute offered rate 0 bps, drop rate 0 bps

          Match: protocol rtp

          Match: ip dscp ef (46)

          Queueing

            Strict Priority

            Output Queue: Conversation 40

            Bandwidth 64 (kbps) Burst 1600 (Bytes)

            (pkts matched/bytes matched) 0/0

            (total drops/bytes drops) 0/0
        Class-map: DATA (match-all)

          0 packets, 0 bytes

          5 minute offered rate 0 bps, drop rate 0 bps

          Match: ip dscp cs1 (8)

          Match: fr-dlci 112

          Queueing

            Output Queue: Conversation 41

            Bandwidth 128 (kbps) Max Threshold 64 (packets)

            (pkts matched/bytes matched) 0/0

        (depth/total drops/no-buffer drops) 0/0/0
        Class-map: class-default (match-any)

          1040 packets, 95287 bytes

          5 minute offered rate 0 bps, drop rate 0 bps

          Match: any

          Queueing

            Flow Based Fair Queueing

            Maximum Number of Hashed Queues 32

        (total queued/total drops/no-buffer drops) 0/0/0
    Class-map: class-default (match-any)

      2594 packets, 153695 bytes

      5 minute offered rate 0 bps, drop rate 0 bps

      Match: any

Verify fragmentation settings:

Rack1R1#show interface serial 0/0/0:0

Serial0/0/0:0 is up, line protocol is up

  Hardware is GT96K Serial

  MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation FRAME-RELAY, loopback not set

  Keepalive set (10 sec)

  LMI enq sent  21224, LMI stat recvd 21224, LMI upd recvd 0, DTE LMI up

  LMI enq recvd 0, LMI stat sent  0, LMI upd sent  0

  LMI DLCI 1023  LMI type is CISCO  frame relay DTE

  FR SVC disabled, LAPF state down

  Fragmentation type: end-to-end, size 640, PQ interleaves 0   <--------- Fragment Size

  Broadcast queue 0/64, broadcasts sent/dropped 63160/0, interface broadcasts 56080

  Last input 00:00:03, output 00:00:02, output hang never

  Last clearing of "show interface" counters 2d10h

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 6

  Queueing strategy: weighted fair

  Output queue: 0/1000/64/0 (size/max total/threshold/drops)

     Conversations  0/1/256 (active/max active/max total)

     Reserved Conversations 0/0 (allocated/max allocated)

     Available Bandwidth 1152 kilobits/sec

  5 minute input rate 0 bits/sec, 1 packets/sec

  5 minute output rate 0 bits/sec, 1 packets/sec

     272202 packets input, 27557680 bytes, 0 no buffer

     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

     15 input errors, 15 CRC, 8 frame, 0 overrun, 0 ignored, 5 abort

     333676 packets output, 42152431 bytes, 0 underruns

     0 output errors, 0 collisions, 16 interface resets

     0 output buffer failures, 0 output buffers swapped out

     0 carrier transitions

  Timeslot(s) Used:1-24, SCC: 0, Transmitter delay is 0 flags