E1 Link errors caused by clocking

[Jimtron26]

Hi all,

I have recently installed 2 1721 routers between 2 sites that are providing a connection across an E1 circuit. The routers have WIC-1Ts installed in them which in turn connect to DC1000 modems providing the media conversion between X.21 and G703. The link provides both internal voice and data.

Recently my customer has been complaining that users at site 2 (who use the link to connect to servers at site 1) have been bombed out of certain applications and that the quality of the voice is sometimes "flaky".

I have checked the config of my routers which are fine (IP based QoS is in use) but I am seeing hundreds of thousands of errors on the serial interfaces of each router.

I have spoken to an independant consultant who is pointing the finger at the DC1000 modems at each site and saying that they are not clocking with each other correctly.

There are 4 clock settings on these modems which are configured by dip switch which are as follows:

Internal
E1 Loop
Terminal
DTE Mode

I have no clue at all which of these settings should be set on each modem, i simply took them out of the box and plugged them in! I have been searching on the internet for about an hour now with no luck apart from finding out how much the damn things cost.

I know this isnt striclty a cisco query but i would appreciate any advice that will shed some light as to what settings i should put the modems on, is it E1 specific? etc

many thanks in advance

Jim
(CCNA exam on monday!!!)

 

[mainstreetexpress]

Hi Jim
Set them to E1 loop, this means that they will get clocking off the network, incidentally what are they currently set to at the moment?

 

[Jimtron26]

Thanks for the response but ive sorted it now!!!

Both modems were set to Loop out of the box. One end needs to be set to E1 loop and the other internal!! Data fine, voice still flaky but going to take the compression off the Avaya cassettes

(Just in case you ever need to know!!!)

Thanks anyway