Newbie question on problems with a 1720

[101glt101]

Hi,

I am new to the forum. Please point me in the right

direction if this is not the correct place for this

post.

I have a Cisco 1720 router which occasionally stops

passing traffic. In some cases the CD light has not

been lit on the CSU/DSU card. The router is connected

to a T1 Demarc. The router stops working whenever

there is maintenance done by the phone company on

the T1 circuit.

To coax the router back to life we have to power it

off for at least 10 minutes.

My questions:

1) What is the normal length of time such a router

should be left powered off for when power cycling?

2) Is it normal behaviour for such a router to be

unable to recover after the T1 line has suffered a

problem.

I am sorry for the vagueness of the description of

the issues, but I do not have access to the routers

themselves to be able to determine the nature of the

issues.

In vain hope of help,

Geoff Taylor

[smif101]

No this is not normal behavior for the router. You can reboot it whenever you want and everything should work fine. It might be a bug in your code if you think it is the router, but if the circuit is brought down and then back up the router should see this and act appropialtly. What version of code are you running on this 1720 router. Also do you have a spare T1 card for your router, that might be flaking out too.

[rais]

There is no hard and fast rule to keep the router powered-off when cycling the power. Few seconds should do it. I would also power-cycle the CSU/DSU if it's external to the router and if router was rebooted due to T1 problems.

Normally, router connected to a T1 circuit should not be power-cycled after T1 comes up. You should have your telco check this problem.

Hope this helps.

[thisisshanky]

When the phone company does maintenance, the T1 line goes down. But there is no reason your router should go down because of this. When the T1 comes back up, does the CSU/DSU CD lights as well as the serial interface on the router shows up ? A show interface command on the router should reveal the status. To check to see if your WIC is bad or the circuit is bad, use the following docs for troubleshooting.

http://www.cisco.com/en/US/tech/tk713/tk628/tech_tech_notes_list.html

[101glt101]

Hi guys,

Thanks for the responses.

Sorry, but I don't know the code version on the

router. As I say, we don't have access. I'll try

to find out from our ISP though.

Shanky, you ask:

"When the T1 comes back up, does the CSU/DSU CD

lights as well as the serial interface on the router

shows up?"

I think the answer is no. Certainly in one instance

of this problem, the CSU/DSU light on the card did

not light, but the Serial Interface was down at that

time too.

I think, from what you are all saying, that there is

a fault in the router somewhere. Now I know that, I

can tell the ISP to look more carefully at the

router in question. I think they are sometimes a

little quick to blame the circuit first.

Thanks again for your answers.

Cheers,

Geoff.