Serial up, line protocol down

[billberge]

Hey Experts,

I’ve installed a new T1 VWIC2 card in a Cisco 2621 to replace an existing T1 CSU/DSU card. The card is recognized by the router and the T1 controllers and serial interfaces are configured correctly. When the old T1 CSU/DSU card is installed the P2P T1 line comes up just fine and traffic is being passed. When the T1 VWIC2 card is installed the new serial interface comes up but the line protocol is down. The serial interfaces are configured and addressed the same. The clocking on the near and far end routers T1 controllers are both set to line. I have a TAC case open with Cisco on this but they were unable to figure out why the line protocol would not come up during the 2 hour maintenance window we had to work with. We ran loopback tests in which the line protocol can up fine to eliminate the possibility of a hardware problem on the new card. No errors. Also checked and all of the interfaces and controllers are not administratively shutdown.

Not sure why this line protocol will not come up. Help anyone?

Thanks in advance.

 

[North323]

thats a layer 2 issue

can you post a scrubbed config?

 

[billberge]

Don't have an available config to post. I had to roll back to get the site back online. Here's how the routers are configured.

Cisco 2621 (New Card installed here)
controller t1 0/0
framing esf
linecode b8zs
cablelength short 133
channel-group 1 timeslots 1-24
description Data T1

!
controller t1 0/1
shutdown
framing esf
linecode b8zs
channel-group 1 timeslots 1-24

!
!
interface Serial0/0:1
description connection to Detroit
bandwidth 1544
ip address 192.168.254.5 255.255.255.252
ip route-cache flow
auto qos voip trust
service-policy output AutoQoS-Policy-Trust

FAR END (Cisco 2811)
controller T1 0/1/0
framing esf
linecode b8zs
cablelength short 133
channel-group 0 timeslots 1-24
description Data T1
!
controller T1 0/1/1
shutdown
framing esf
linecode b8zs

interface Serial0/1/0:0
bandwidth 1544
ip address 192.168.254.6 255.255.255.252
ip summary-address eigrp 100 10.2.0.0 255.255.0.0 5
auto qos voip trust
service-policy output AutoQoS-Policy-Trust

Again, clocking is set to line on each end. I tried internal as well witht the same results.

Thanks for any help.

 

[jeter]

Do you have access to the circuit? What errors are on the circuit card (NIU)?

Sh interface serial0/0:1 to verify no loops on the circuit.
Also verify both ends are setup with HDLC or PPP! They must match.

Go Army!
Tek-TIP Member 19,650

 

[billberge]

jeter, we ran loopback test on the vwic cards no errors. When the old T1 CSU/DSU card is installed back in the 2621 the line comes up fine and is clean and traffic flows. No loops anywhere.

 

[jeter]

The circuits goof then... Did you verify that your using hdlc or ppp on both routers?

Also I'm wondering it could be a clocking issue.

example
!
network-clock-participate slot 1
network-clock-participate wic 0
network-clock-participate wic 1
network-clock-participate wic 2
network-clock-select 1 T1 0/2/0

Go Army!
Tek-TIP Member 19,650

 

[billberge]

jeter, first thanks for you help. running HDLC on both ends. tried PPP still no luck. thinking it's also a clocking issue.

 

[whykap]

if its a clocking issue you should be seeing crc errors.
When the VWIC is in type
"show controllers T1"
With jeters commands you should be able to fix the clocking issue it that's what it is.

 

[burtsbees]

Not sure, but shouldn't the channel-group number match the first timeslot?

channel-group 0---should this not be "1", since the timeslots start with 1 (Far End, C2811)? Or does it not matter, just a logical identifier?

Also, what about this?

cablelength short 133

Wouldn't you want the "no" form of that in this case?

http://www.cisco.com/en/US/docs/rou...ftware/command/reference/E1T1ref.html#wp32108

Just a couple of stabs in the dark..

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[jeter]

The channel group was nagging at me as well but I could not remember.

Go Army!
Tek-TIP Member 19,650

 

[billberge]

Thanks everyone. I have a maintenace window setup for tomorrow evening with Cisco to once again try and get this card to work. I'll let you all know what the outcome is.

 

[billberge]

Just finished working the case with TAC. Turned out that on the T1 controller we needed to set the speed on the channel group in order to bring up the line protocol. Once we added "channel-group 1 timeslots 1-24 speed 64" the T1 came up just fine. Thanks everyone for reply to this post.