T1 config: service-module t1 clock source internal

lwwarner

In another thread about T1 cabling, Mike said:

mikej412 wrote: »

... and don't forget the service-module t1 clock source internal on one side of the connection

Is this command really needed? My T1 crossover connection comes up just fine without it. Both sides are up & up, they both show "Framing is ESF, Line Code is B8ZS, Current clock source is line," and "Hardware is PowerQUICC MPC860 with Integrated FT1 CSU/DSU module TX and RX clocks detected."

Both sides are 2651XM/WIC-2T/WIC-1DSU-T1 boxes running Cisco IOS Software, C2600 Software (C2600-ADVENTERPRISEK9-M), Version 12.4(23), RELEASE SOFTWARE (fc1).

??

tiersten

Yes. It is needed. It will come up but it is unreliable because it isn't synchronised. It won't operate correctly if one end isn't providing a clock. Try sending data over that link and look at the counters for errors.