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Community Member

Slow Frame Relay connection on Cisco 805 platform


I have several 56k frame-realy sites that have an 805 router. The 805 routers replaced old 3com Netbuilder routers, although the circuit did not change at all. I used to be able to drive these circuits at 56k, but since the introduction of the 805's, I can't seem to drive the line beyond about 20k. We have done a lot of work with the carrier to determine what the problem might be, but we are coming up blank. We have even increased the CIR to 56k at one site to no effect. Basicaly, I can't get the interface to transmit at more than 118/255 - that's where the serial connection sits. This is across PVC's that are Frame to ATM and FRame to FRame. Here's a sample config piece from my 805:

St-Georges#sh run int ser 0

Building configuration...

Current configuration : 224 bytes


interface Serial0

bandwidth 56

no ip address

encapsulation frame-relay IETF

no fair-queue

frame-relay class thomas

frame-relay traffic-shaping

frame-relay lmi-type cisco

hold-queue 256 in

hold-queue 1024 out


St-Georges#sh run int ser 0.18

Building configuration...

Current configuration : 211 bytes


interface Serial0.18 point-to-point

description Frame-relay connection to Winnipeg ATM interface

bandwidth 56

ip address

no cdp enable

frame-relay interface-dlci 18 IETF


St-Georges#sh run int ser 0.502

Building configuration...

Current configuration : 148 bytes


interface Serial0.502 point-to-point

bandwidth 56

ip address

no cdp enable

frame-relay interface-dlci 502 IETF


Show Frame-relay-map:

St-Georges#sh frame-relay map

Serial0.18 (up): point-to-point dlci, dlci 18(0x12,0x420), broadcast, IETF, BW =


status defined, active

Serial0.502 (up): point-to-point dlci, dlci 502(0x1F6,0x7C60), broadcast, IETF,

BW = 48000

status defined, active

One other note of interest - When I run an end to end ping, the utilization climbs very very slowly - takes about 3 minutes to get to the 118/255 utilization.

Oh - Sh int ser 0:

St-Georges#sh int ser 0

Serial0 is up, line protocol is up

Hardware is PowerQUICC Serial

MTU 1500 bytes, BW 56 Kbit, DLY 20000 usec,

reliability 255/255, txload 4/255, rxload 4/255

Encapsulation FRAME-RELAY IETF, loopback not set

Keepalive set (10 sec)

LMI enq sent 4046, LMI stat recvd 4046, 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

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

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

Last clearing of "show interface" counters 11:14:38

Input queue: 0/256/1/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/1024 (size/max)

5 minute input rate 1000 bits/sec, 2 packets/sec

5 minute output rate 1000 bits/sec, 2 packets/sec

49882 packets input, 4569527 bytes, 0 no buffer

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

2 input errors, 0 CRC, 2 frame, 0 overrun, 0 ignored, 0 abort

65469 packets output, 5076968 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=up

Any ideas would be very welcome..

Community Member

Re: Slow Frame Relay connection on Cisco 805 platform

Figured I should add a show ver:

St-Georges#sh ver

Cisco Internetwork Operating System Software

IOS (tm) C805 Software (C805-SY6-MW), Version 12.3(9), RELEASE SOFTWARE (fc2)

Copyright (c) 1986-2004 by cisco Systems, Inc.

Compiled Fri 14-May-04 16:48 by dchih

Image text-base: 0x0017F000, data-base: 0x00B3A000

ROM: TinyROM version 1.4(1)

St-Georges uptime is 11 hours, 16 minutes

System returned to ROM by reload

System restarted at 03:30:24 UTC Fri Mar 3 2006

System image file is "flash:c805-sy6-mw.123-9.bin"

Cisco C805 (MPC850) processor (revision 0) with 50000K bytes of virtual memory

Processor board ID FOC082100V3 (36382350)

CPU part number 0x2101

Bridging software.

X.25 software, Version 3.0.0.

1 Ethernet/IEEE 802.3 interface(s)

1 Serial(sync/async) network interface(s)

8M bytes of physical memory (DRAM)

8K bytes of non-volatile configuration memory

8M bytes of flash on board (4M from flash card)

Configuration register is 0x2102

I'm not posting a show buffers, but it is very clean as well..

Community Member

Re: Slow Frame Relay connection on Cisco 805 platform


1. Check why you have input errors. Clear counters and test again, make sure the line is clean.

2. When configuring the class under the main interface all your sub-interfaces will inherit that class. Is your Traffic shapping correct?

Perhaps you can post

(a) the config of the map-class frame-relay...

(b) let us know what the cir of each pvc is

(c) the output of sh traffic-shape intx/y



Community Member

Re: Slow Frame Relay connection on Cisco 805 platform

Thanks for the reply ...

map-class frame-relay thomas

frame-relay traffic-rate 56000 56000

frame-relay cir 56000

frame-relay mincir 56000

I've tried this with several values, even without the map-class at all. Tried with and without trafic shaping at all, and I get the same poor results.

The CIR for this site is 56k, so I know I should not be throttled there.

Sh traffic-shape ser 0:

St-Georges#sh traffic-shape ser 0

Traffic shaping not configured on Serial0

St-Georges#sh traffic-shape ser 0.18

Interface Se0.18

Access Target Byte Sustain Excess Interval Increment Adapt

VC List Rate Limit bits/int bits/int (ms) (bytes) Active

18 56000 875 56000 0 125 875 -


As I said, I have at 7 or 8 sites that behave like this. Generally, the configs are very vanilla - no traffic shaping and only an interface DLCI specified. Last night I worked with our carrier trying to figure this out, and it's very perplexing. No errors after running an extended ping of large packets, just poor throughput. No FECN, No BECN, no errors, no input or output drops??? I did all of this testing withour registering an input error (the counter is still at 2 as I type this), yet no matter what I cannot drive the line anywhere near the CIR?

Community Member

Re: Slow Frame Relay connection on Cisco 805 platform

Try this see what happens, only showing relevant commands, but do remove the frame-relay class thomas

from the physical. Also do this on the remote router.

interface Serial0

frame-relay traffic-shaping

map-class frame-relay TEST

frame-relay cir 60000

frame-relay bc 7500

frame-relay be 500

frame-relay mincir 56000

frame-relay adaptive-shaping becn

interface Serial0.502 point-to-point

frame-relay interface-dlci 502 IETF

class TEST

The above instructs the router to send traffic at 60k with burst up to 64k but will throttle back when becns are received, to 56k.

BTW, is your line clean? Any errors?

And another thing, what is the access-rate of the physical port? Does the service provider allow you to burst up to the port speed?



Community Member

Re: Slow Frame Relay connection on Cisco 805 platform

Thanks E...

doesn't seem to make a difference. The port speed on the physical port is 64k, pvc is 56k. I'm not sure if I can burst to 64k, but I don't think I can - never saw a speed over 56k before. I do notice there are often packets in the hold queue, input and output. Have tried different queuing mechanisms with no measurable difference. Also, I am seeing some FECN packets on this pvc now, not a lot, but a few -212 FECN's since last Thursday. Really at a loss as to what is happening here. I am leaning towards trying to code the clocking for this line and see what happens.

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