ATM 8510 back to back with 7206vxr 155Meg only get 44Meg issue

[pete.small]

    I have a Cisco 8510msr that is connected back to back with a 7206vxr across a 155Meg connection.

I receive lots of Output drops on the 7206vxr interface facing the atm switch.

When I do the following command:-

kwdair9#sh atm int atm 1/0
Interface ATM1/0:
AAL enabled:  AAL5 , Maximum VCs: 4096, Current VCCs: 27

Maximum Transmit Channels: 0
Max. Datagram Size: 4528
PLIM Type: SONET - 155000Kbps, TX clocking: LINE
Cell-payload scrambling: ON
sts-stream scrambling: ON
797522 input, 881483 output, 203946630 IN fast, 223768062 OUT fast, 0 out dropVBR-NRT : 110288
Avail bw = 44712                 <====   I only have 44meg
Config. is ACTIVE
kwdair9#

I only get 44Meg of the available 155Meg.

There is no QOS on the router and the only commands I can find that vaguely see that refer to QOS are on the ATM switch:-

atm address 47.0091.8100.0000.0007.0d87.b201.0007.0d87.b201.00
atm router pnni
no aesa embedded-number left-justified
node 1 level 56 lowest
  redistribute atm-static

Can anyone suggest why this is acting like a DS3 link and not a 155Meg link??

[amikat]

Hi,

It is likely that you have configured some atm pvc at your 7206vxr box with the guaranteed cell rate (e.g. vbr-nrt service category). Will you please post the "show atm vc" command output (issued at 7206vxr router).

Best regards,

Antonin

[pete.small]

kwdair9#kwdair9#sh atm vc
           VCD /                                        Peak  Avg/Min Burst
Interface  Name         VPI   VCI  Type   Encaps   SC   Kbps   Kbps   Cells  Sts
1/0.26     gardner-bdc    1    32  PVC    SNAP     VBR    1920   1920    94   UP
1/0.28     geaviation-b   1    33  PVC    SNAP     VBR    6000   6000    94   UP
1/0.29     bdc-baesys     1    34  PVC    SNAP     VBR    3000   3000    94   UP
1/0.32     bdc-quest      1    35  PVC    SNAP     VBR   10000  10000    94   UP
1/0.31     bdc-wsatkins   1    36  PVC    SNAP     VBR    8000   8000    94   UP
1/0.33     bdc-darchem    1    37  PVC    SNAP     VBR     512    512    94   UP
1/0.34     bdc-aerosys    1    38  PVC    SNAP     VBR   10000  10000    94 DOWN
1/0.24     bdc-xer        2    32  PVC    SNAP     VBR    1920   1920    94   UP
1/0.7      bdc-ged        3   101  PVC    SNAP     VBR    1920   1920    94 INAC
1/0.10     bdc-stir       4    32  PVC    SNAP     VBR    1920   1920    94   UP
1/0.17     fil-frz        4    33  PVC    SNAP     VBR    1920   1920    94   UP
1/0.2      bdc-meri       4    34  PVC    SNAP     VBR     256    256    94   UP
1/0.22     kwd9-cab       4    35  PVC    SNAP     VBR    1024   1024    94   UP
1/0.8      bdc-lion       4    36  PVC    SNAP     VBR    1920   1920    94   UP
1/0.4      fil-mor2       4    37  PVC    SNAP     VBR    4000   4000    94   UP
1/0.12     kwd9-aer1      4    38  PVC    SNAP     VBR    1000   1000    94 INAC
1/0.21     kwd9-par       4    39  PVC    SNAP     VBR    1024   1024    94   UP
1/0.9      bdc-xype       5   101  PVC    SNAP     VBR    1920   1920    94   UP
1/0.1      hyde1          6   101  PVC    SNAP     VBR   10000  10000    94   UP
1/0.3      kwd-infosys    7   101  PVC    SNAP     VBR    1920   1920    94   UP
1/0.23     hami-bdc       8    32  PVC    SNAP     VBR     512    512    94   UP
1/0.30     bdc-sitec      9    32  PVC    SNAP     VBR   10000  10000    94   UP
1/0.25     bdc-assys     10    32  PVC    SNAP     VBR   20000  20000    94   UP
1/0.18     fil-bea       11    32  PVC    SNAP     VBR    1920   1920    94   UP
1/0.11     bdc-goodrich  12   101  PVC    SNAP     VBR    1920   1920    94   UP
1/0.14     bdc-ara       15   101  PVC    SNAP     VBR    1920   1920    94   UP
1/0.20     fil-acc       17   101  PVC    SNAP     VBR    1920   1920    94   UP
1/0.27     morsons-bdc   18   101  PVC    SNAP     VBR    1920   1920    94   UP
kwdair9#

[amikat]

Hi,

Thanks for the information provided.

It clearly displays what I have expected: you (or somebody else) have configured quite a number of ATM PVCs with the guaranteed cell rate. The math for the "Avail bw" parameter you are questioning is very simple: this equals the full BW of the OC3/SONET interface (which is 155 000 Kbps) minus the sum of all the guaranteed bw for the PVCs configured. In your case of the VBR service category the guaranteed bw for a PVC is equal to the SCR parameter (eg. 1920 kbps for the first PVC of your list). If you add all SCR values of your ATM PVCs list you come to the value of 110 288 Kbps. Thereafter you get:

Avail bw = 155 000 - 110 288 = 44 712 (Kbps),

which is the bw available for all the other possible ATM VCs (PVCs or SVCs) without the configured guaranteed cell rate.

So as you can see your OC3 board is acting as expected (at least as for the "Avail bw" parameter calculation).

I hope my English makes sense.

Best regards,

Antonin

[pete.small]

Thanks very much for that!! You've answered this perfectly.

Sent from Cisco Technical Support iPhone App