T1 connection problem with 1721 and WIC-1DSU-T1-V2

[tojorand]

My school recently purchased a T1 to connect our admin office to another building across town. At one end of the T1, we have a Cisco 2801 router with a WIC-1DSU-T1-V2 card, and at the other end we have a Cisco 1750 with a WIC-1DSU-T1 card in it. We are using PPP across the link and RIP version 2. When configuring the T1 module, we used all the default settings. For nearly four weeks, the T1 ran without a hitch, but after we swapped out the 1750 for a 1721 with a WIC-1DSU-T1-V2 card (the 1750 was a loaner), we can't get the T1 to come back up.

We are using the same configuration on the 1721 that we had on the 1750. The T1 will come up for maybe two minutes and then be down for ten hours. When it is up, all routing updates are passed throughout the network and everything works fine, but two or three minutes later, the T1 goes down again indefinitely.

The 1721 says it is transmitting remote alarm and receiver has no alarm. The 2801 says it is receiving remote alarm and transmitter has not alarms. We have run loopback commands on the routers and the alarms have cleared, and the telephone company has looped their lines and the alarms have cleared, but the routers still will not talk to each other.

Here is the 2801 running config:

ADMIN#show run
Building configuration...

Current configuration : 1436 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname ADMIN
!
boot-start-marker
boot-end-marker
!
logging buffered 51200 warnings
enable secret
!
mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
no aaa new-model
ip subnet-zero
ip cef
!
!
!
!
no ftp-server write-enable
!
!
!
!
interface FastEthernet0/0
description To ADMIN Ethernet
ip address 172.16.0.5 255.255.224.0
duplex auto
speed auto
!
interface FastEthernet0/1
description To PIX
ip address 172.16.64.2 255.255.248.0
duplex auto
speed auto
!
interface Serial0/1/0
description T1 to JH
ip address 172.16.32.9 255.255.255.252
encapsulation ppp
service-module t1 clock source internal
!
interface Serial0/2/0
description T1 to HS
ip address 172.16.32.5 255.255.255.252
encapsulation ppp
service-module t1 clock source internal
!
router rip
version 2
network 172.16.0.0
no auto-summary
!
ip classless
ip route 0.0.0.0 0.0.0.0 172.16.64.1
ip http server
ip http authentication local
!
!
!
control-plane
!
banner motd ^CT1 ADMIN Router^C
!
line con 0
login local
line aux 0
line vty 0 4
privilege level 15
password
login
transport input telnet
line vty 5 15
privilege level 15
login local
transport input telnet
!
end


The 1721 running config:

HS#show run
Building configuration...

Current configuration : 837 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname HS
!
boot-start-marker
boot-end-marker
!
enable secret
!
mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
no aaa new-model
ip subnet-zero
ip cef
!
!
!
no ftp-server write-enable
!
!
!
!
interface FastEthernet0
description Connected to HS Ethernet
ip address 172.16.40.1 255.255.248.0
speed auto
full-duplex
!
interface Serial0
description T1 to ADMIN
ip address 172.16.32.6 255.255.255.252
!
router rip
version 2
network 172.16.0.0
no auto-summary
!
ip classless
ip route 0.0.0.0 0.0.0.0 172.16.32.5
no ip http server
!
!
line con 0
line aux 0
password
login
line vty 0 4
password
login
!
!
end


And the 1750 running config:

HS#show run
Building configuration...

Current configuration : 764 bytes
!
version 12.2
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname HS
!
logging queue-limit 100
enable secret
!
memory-size iomem 25
no ip subnet-zero
!
!
!
!
!
!
!
interface FastEthernet0
description Connected to HS Ethernet
ip address 172.16.40.1 255.255.248.0
speed auto
full-duplex
!
interface Serial0
description T1 to ADMIN
ip address 172.16.32.6 255.255.255.252
encapsulation ppp
!
router rip
version 2
network 172.16.0.0
no auto-summary
!
ip classless
ip route 0.0.0.0 0.0.0.0 172.16.32.5
no ip http server
!
!
!
line con 0
line aux 0
line vty 0 4
password
login
!
no scheduler allocate
end


What gets me is the 1750/2801 combination works great, but the 1721/2801 combination doesn't work at all. I would appreciate any help or insights you may have. Thanks in advance.

 

[jneiberger]

You might want to open up a TAC case if you have a support contract. I've been hearing rumors that the new WIC-1DSU-T1-V2 modules are very buggy and prone to failure. You may simply have a bad WIC.

Regards,
John

 

[JOAMON]

Hello....

Dont know if you already have this solved but if not this may help. You need ppp encap on 1721 t1 interface.

Hope it helps

 

[jneiberger]

Oh, yep, JOAMON is right. I missed that! <smacking hand on forehead>

You have mismatched encapsulations. Fix that and all should be well.

 

[JOAMON]

Sometimes hardest things to fix are those hidden in plain sight!!!!

 

[tojorand]

Thanks for all your help guys.

I fixed the encapsulation problem and still no go.

When we put a hard loopback plug in, no alarms cleared. Called Cisco and they sent a new card. Works great now (especially when the encapsulations match )

 

[JOAMON]

Good News....

Cisco WIC-1DSU-T1-V2 are extremely buggy. I have gone through 5 new cards and still only have two functional. Have Cisco 2811 and need three point to point t1 connections. Problem is 3 of the five cards received only work in slot one. Not comfortable with a buggy card that only works in slot one. Cisco really needs to work on these cards. You cant even use this card as clock source in point to point to WIC-1DSU-T1 card. Must clock from the WIC-1DSU-T1 card.

 

[tojorand]

Yeah, I understand why you would be uncomfortable. When we were putting in the T1s, one link (with V2 cards at both ends) was down at 6:00pm one day and up the next day by 8:00am. It's been solid ever since, but who knows when it will go down again? I hope Linksys' stuff hasn't made its way into these cards.