Re: Frame-Relay LMI

somanabich · ‎01-11-2002

I have just installed a Frame-Relay circuit, and connected my router with following configuration

interface Serial3/2

bandwidth 512

no ip address

encapsulation frame-relay

frame-relay lmi-type q933a

!

interface Serial3/2.16 point-to-point

description PVC to remote site 1

ip address 192.168.245.254 255.255.255.252

frame-relay interface-dlci 16

!

interface Serial3/2.17 point-to-point

description PVC to remote site 2

ip address 192.168.245.250 255.255.255.252

frame-relay interface-dlci 17

My FR link won't come up and when I do a 'show int s3/2' I get the following output

Serial3/2 is up, line protocol is down

Hardware is DSCC4 Serial

MTU 1500 bytes, BW 512 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 666, LMI stat recvd 0, LMI upd recvd 0, DTE LMI down

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

LMI DLCI 0 LMI type is CCITT frame relay DTE

My Frame-Relay provider tells me that one possible cause that the LMI Status is down is because I haven't installed my remote end yet, so the PVC can't be establsied, thus LMI status is down.

I thought LMI was a 'local' negotiation protocol between the DTE(my router) and the FR providers switch(DCE).

Is my provider correct, and if so could it be causing the problem I am seeing above?

Thanks in advance

DELL ACORD · ‎01-11-2002

Do the following commands on your router.

1). Sh frame-relay map.

2). sh frame-relay pvc.

3). sh controllor serial 3/2.

Look at the output of the cmds.

you should see an stable and correct PVC. DLCI clock and circuit speed. If not contact your local telco and have them check the circuit. There could be a telco switching problem or a config problem at the telco switch.

MickPhelps · ‎01-11-2002

Your local provider is incorrect.

The main interface serial3/2 will come up/up when it receives LMI from the frame switch regardless of the remote status.

Your P2P sub-ifs will be down/down.

Please attach a full SHOW INT S3/2. You could have other line errors that is keeping you down.

Mick.

somanabich · ‎01-13-2002

That's what I thought, that at least on the physical interface I should be getting LMI updates. Could it be an issue with LMI Keepalive updates timing?

Here is the output of the 'sh interface s3/2'

Serial3/2 is up, line protocol is down

Hardware is DSCC4 Serial

MTU 1500 bytes, BW 512 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 23586, LMI stat recvd 0, LMI upd recvd 0, DTE LMI down

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

LMI DLCI 0 LMI type is CCITT frame relay DTE

Broadcast queue 0/64, broadcasts sent/dropped 2/0, interface broadcasts 0

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

Last clearing of "show interface" counters 2d18h

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

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 384 kilobits/sec

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

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

0 packets input, 0 bytes, 0 no buffer

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

1 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 1 abort

23630 packets output, 307762 bytes, 0 underruns

0 output errors, 0 collisions, 8007 interface resets

0 output buffer failures, 0 output buffers swapped out

1 carrier transitions

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

Also here the output of 'sh frame-relay lmi'

LMI Statistics for interface Serial3/2 (Frame Relay DTE) LMI TYPE = CCITT

Invalid Unnumbered info 0 Invalid Prot Disc 0

Invalid dummy Call Ref 0 Invalid Msg Type 0

Invalid Status Message 0 Invalid Lock Shift 0

Invalid Information ID 0 Invalid Report IE Len 0

Invalid Report Request 0 Invalid Keep IE Len 0

Num Status Enq. Sent 23625 Num Status msgs Rcvd 0

Num Update Status Rcvd 0 Num Status Timeouts 23624

Thanks for your help.

MickPhelps · ‎01-14-2002

The problem is that you're not getting anything. You're not reciving LMI or errors. Verify your framing and linecoding. Also, run loopback tests locally and from the CO to verify that you have a good signal path.

If your timers were off, you would still be receiving LMI, but your interface might be flapping.

Mick.

pverlouw · ‎01-14-2002

Classic problem: most likely your lmi type is wrong. Of 3 different types you chose q933a which is ITU-T. Other options are cisco (default) or ansi. You MUST use the same lmi type as your provider, so you could ask.

The quick way is to try it by changing the type. Don't forget the shut/noshut the interface or wait some 5 minutes.

The other problem that might hit you is that the dlci's that you use need to be the same as the ones that your provider uses. A wrong dlci will keep your subinterface down. The only way to find this out is to ask them!

MickPhelps · ‎01-14-2002

The problems that you've listed here are definately valid, but I don't think that he's having them.

Check out his interface stats. 0 input packets on the main interface. LMI should show up there if he's receiving *any* packets, even LMI, right?

Mick.

pverlouw · ‎01-14-2002

You could be right, but there's still the possibility that the carrier uses Cisco lmi. Ansi and ITU-T communicate on dlci 1023, cisco not. And I'm pretty sure that you won't see ANY input packets until the lmi-types match.

somanabich · ‎01-15-2002

Well, after about a day of my Telco checking their network the problem was not with the configuration of my router.

Interesting was that after they fixed the problem a 'sh frame pvc' showed the status from 'Deleted' to 'Inactive' (because I haven't connected my other ends yet...) and LMI Status showed that it was UP.

Thanks for everyones help!

mbjohnson · ‎01-15-2002

Just remember one thing..it's 95% of the time the Telco's fault! :)

lolly · ‎01-15-2002

If you type 'show frame pvc' you will get all the paths (FRC's) that are currently configured within the service providers network. This will confirm if your dlci is configured correctly.

ie DLCI = 450, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0.2 (config correctly)

DLCI = 251, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0 (subinterface not config on router). Also lmi type is auto detect on resent releases of ios. Removed the lmi type and see what comes up. Is the service provider seeing lmi from you? Also check cabling between router and NTU.