ISDN connection from remote site to local router not working

dtecco · ‎02-20-2008

Hello all,

We have a 1721 at a remote location, and a 2821 at our local site. We are trying to get the remote site to call in and connect to our local site via ISDN. The 1721 has a BRI interface. The 1821 has a PRI interface.

The 1721 ISDN connection attempt almost immediately dies. The 1821 does not even receive any traffic coming in. Both circuits have been tested and verified by the ISPs.

It seems that I am missing something in the config.

I am attaching the config of the remote router that is trying to initiate the connection, the config snippet of the local router that is supposed to receive the connection, and the ISDN debug outputs/status of the remote router.

I have a ticket open with TAC, but they have not been very helpful so far. Does anyone notice anything wrong/missing in the configs? I find it reasonably hard to believe this is a problem with the ISPs at this point.

Thanks,

Richard Burts · ‎02-20-2008

Dave

I have looked at what you posted and I believe that I see several things that would be problems (such as the fact that the remote router does not configure ppp authentication on its BRI while the local does have ppp authentication) but I do not believe that you have yet gotten to the point where that would be an issue.

In looking at the output that you posted I am focused on this:

*FEB 20 8:38:13.991: ISDN BR0 Q931: DISCONNECT pd = 8 callref = 0x86

Cause i = 0x84A2 - No circuit/channel available

Signal i = 0x03 - Network congestion tone on

That appears to me to indicate that there is an issue between your router and the ISDN switch.

HTH

Rick

HTH

Rick

smothuku · ‎02-21-2008

Hi ,

Can you change the config as per below and check the issue.

Local Router :

username XXXX(Remote rouetr name) password XXXXXX

controller T1 1/0

framing esf

linecode b8zs

cablelength long 0db

pri-group timeslots 1-24

!

interface Serial1/0:23

description ISDN PRI circuit xxxxx

no ip address

encapsulation ppp

dialer pool-member 1

isdn switch-type primary-5ess

no peer default ip address

no cdp enable

ppp authentication chap

ppp multilink

!

interface Dialer1

description ISDN connect to REMOTE_RTR via xxxx

ip address 192.168.30.5 255.255.255.252

encapsulation ppp

dialer pool 1

dialer caller xxxyyy1384

dialer caller xxxyyy1390

dialer-group 1

dialer-remote name Remote router

no cdp enable

ppp authentication chap

ppp multilink

!

dialer-list 1 protocol ip permit

!

Remote router :

username local router password XXXX

interface BRI0

description ISDN connect to LOCAL_RTR via xxxx

ip address 192.168.30.6 255.255.255.252

encapsulation ppp

dialer idle-timeout 300

dialer string 1xxxyyy6101(Local Router number)

dialer-group 1

isdn switch-type basic-ni

ppp authentication chap

ppp multilink.

dialer-list 1 protocol ip permit

On both the routers u haven't mentioned username and password as you are using chap authentication for ISDN.

Check the switch type configured on the routers is same as that of configured on ISP's switch.

Thanks,

Satish

dtecco · ‎02-21-2008

Thanks, I was not really worried about PPP right now - because like you said it is not even getting to that point.

Satish, your config suggestions make sense... but you think I should remove the SPIDS on the remote router BRI0 interface?

I am going to see what happens with the updated config.

ISDN switch type has been verified by the service providers.

I dont think this is a connectivity issue between the router and the demarc, because layer 1 is saying "ACTIVE", and layer 2 is showing "MULTIPLE_FRAME_ESTABLISHED"

alvin_acar · ‎02-21-2008

Hi dtecco,

I agree with you that Layer 1 and 2 are showing as Active and Multiple_Frame_Established but Layer 3 is not because that is where the ISDN call is being disconnected.

*FEB 20 8:38:13.991: ISDN BR0 Q931: DISCONNECT pd = 8 callref = 0x86

Cause i = 0x84A2 - No circuit/channel available

Signal i = 0x03 - Network congestion tone on

The Disconnect cause code of 0x84A2 means:

84 The public network near the remote user (remote telco switch)

A2 - No channel available - The connection fails because no appropriate channel is available to take the call.

Try the configuration suggested first and if it still fails with the same disconnect code, contact your ISDN provider.