NM-4A/S

2lazybutsmart

We have a 2611 routers that has an NM-4A/S module installed on it. This same router aslo has a WIC-1T on it. This is Router A.

On the other side is a simple 2501. That is Router B.

Now, here's the problem:

We're using a g703e1-u device that's supposed to convert serial-to-ethernet on one side of the link, and then ethernet-to-serial on the other side. This enables the serial link to be carried over an E1 link.

Now if the g703e1-u units are connected to the WIC-1T card, the status and protocol both come up and everything works fine.

However, if the g703e1-u units are connected to one of the serial intefaces on the NM-4A/S modules, the rotuer starts blinking its "activity" led frantically and you can see the input errors on the interface increasing dramatically.

Isn't the NM-4A/S supposed to work like a normal serial interface? Would the fact that the NM-4A/S module only gives speeds of 128kbps be a problem to the g703e1-u device that gives an unframed 2048kbps throughput?

Any help on this issue will be appreciated.
2lbs.

forbesl

2lazybutsmart wrote:

Would the fact that the NM-4A/S module only gives speeds of 128kbps be a problem to the g703e1-u device that gives an unframed 2048kbps throughput?

2lbs,

Yes, therein lies your problem. I found that out the hard way when we tried using a 1544k link with a 2611. It took me about three hours to figure out what the problem was. After finally looking at the serial module part number and discovering it was a 4A/S, I replaced the module with an NM-4T we had on hand and problem solved.

2lazybutsmart

forbesl wrote:

2lazybutsmart wrote:

Would the fact that the NM-4A/S module only gives speeds of 128kbps be a problem to the g703e1-u device that gives an unframed 2048kbps throughput?

2lbs,

Yes, therein lies your problem. I found that out the hard way when we tried using a 1544k link with a 2611. It took me about three hours to figure out what the problem was. After finally looking at the serial module part number and discovering it was a 4A/S, I replaced the module with an NM-4T we had on hand and problem solved.

Did you install the NM-4T on the 2611 or on another router? Because I couldn't install the NM-4Ts on 2611s nor 2611XMs....

2lbs.

forbesl

???

I don't understand why you can't do that. I simply removed the 4A/S module and plugged in the 4T. Are you saying you can't do that, or are you saying you did that and it doesn't work?

2lazybutsmart

It doesn't work. I tried installing the NM-4T on a 2611,2610,2611XM and it doesn't work on any of them.

So I was wondering how it worked for you. Are you sure it was a 2611?

forbesl

Does the router recognize the module when you plug it in? Can you see the serial interfaces in your configuration when you do a "sh run"? If not, then your IOS may not support the interface and you'll have to flash it with a new IOS.

If it does recognize the module, then you might have to purchase a High Speed Serial Interface (HSSI) Network Module NM-1HSSI module for the router:

http://www.cisco.com/en/US/products/hw/routers/ps274/products_data_sheet09186a0080091b8b.html


Quite honestly, I'm don't know how well those serial-to-ethernet converters work and I'm kinda skeptical about that.

forbesl

...or you might need to get one of these:

http://www.cisco.com/en/US/products/hw/routers/ps259/products_data_sheet09186a0080091b9c.html

Cauthon

Looks like the NM-4T isn't supported for any IOS version on the 2600 series.
http://www.cisco.com/en/US/products/hw/routers/ps274/products_tech_note09186a00800a93f3.shtml#topic3

You could get an NM-2W though and add up to 2 WIC-1Ts.

2lazybutsmart

forbesl wrote:

Does the router recognize the module when you plug it in? Can you see the serial interfaces in your configuration when you do a "sh run"? If not, then your IOS may not support the interface and you'll have to flash it with a new IOS.

If it does recognize the module, then you might have to purchase a High Speed Serial Interface (HSSI) Network Module NM-1HSSI module for the router:

http://www.cisco.com/en/US/products/hw/routers/ps274/products_data_sheet09186a0080091b8b.html


Quite honestly, I'm don't know how well those serial-to-ethernet converters work and I'm kinda skeptical about that.

The router doesn't recognize the module at all. And the NM-4T product page doesn't list anything earlier than 2691 routers are supported platforms.

The converters are actually serial to E1 unframed. They work perfectly fine with the WIC-1T and the WIC-2Ts......and perhaps, most likely, the NM-4T.

It would be a lot of easier if you could recall the configuration you had on those machines and what type of hardware/IOS was installed.

2lbs.