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New Member

Cisco 1841 w/ two T1's

we have two sites that are primarily connected to an MPLS Provider.  Each site has an 1841. 

Site A is connected to the MPLS provider on a VWIC-2MFT-T1

Site B is connected to the MPLS provider on a VWIC2-1MFT-T1/E1

The two sites are also connected together with a point to point t1.  Site A utilizes a second VWIC-2MFT-T1 and site B uses a WIC-1DSU-T1-V2 for the point to point connection

The issue is at Site B we are seeing a lot of path code violiations on the point to point circuit.  Telco states they've tested clean both ways, but are seeing timing slips coming from site A.  I have swapped the timing on the P2P T1 back and forth (Site A clock source internal, site B clock source line) and vice versa.

i'm wondering if there is any architectual issues with the 1841 that doesn't truly provide independant clocking on these VWICS.

COuld the clocking across the two T1's at site B be skewing every once in a while and causing the input errors?

  • WAN Routing and Switching

Cisco 1841 w/ two T1's

If you're seeing slips, then you're definitely looking in the right direction with clocking.  Have you asked the provider if their providing clock?  Perhaps you can have them ensure they are, and and set both sides of your P2P to line as the source.

Just my two cents.


New Member

Cisco 1841 w/ two T1's

Tried setting both sides to clock source line and the path code violations continue to occur.  they've told me that they are not providing clock.


Cisco 1841 w/ two T1's

Actually, I misspoke, since it's P2P, you should be providing clock, not the carrier.  Sorry.

As for the circuit, have you tried matching with a VWIC-2MFT-T1 on both ends, since you've got disparate cards in either router?