I have a DS3 unframed connection between Tokyo and HK. At tokyo end it is a Cisco 7200 (PA T3 + card) and at HK it is Cisco 3845 (NM-1T3/E3 card). I am having CRC / input errors on the serial interface on Tokyo side. No patterns, just burst of errors. Checked the settings on both sides all match. Clock source is internal at Tokyo and line at HK end. The cable length though is 180 feet at Tokyo end (can this be a problem ???) Howevere did loop tests from Tokyo end even to the mux at far end. NO errors when using tester for ds3 but errors pop up when router is connected, even on the loop. Line coding is B3ZS, and also "framing c-bit' is given at both side router (SP says this is not an issue as they dnt really look at this etting on router in an unframed ckt case --- Is this true or does the router setting need a change for framing to unframed? There are few ADMs and MUxs between the routers, but all seem to be synced in terms of setting. Any troublehsooting steps or advise to correct this issue is welcome. Any previous experience with such scenarios is also welcome.
hope this link may help u out in ur troubleshooting process...
Rx measured from HX in front of CPE (including coax cable) is around -4.5 dBm. Wanted to know whether this falls under Cisco's acceptable range for a PA-T3+ DS3 adapter ....
few things to check
1. Framing change c-bit
2. DSU bandwith...should match with the network DSU bandwidth define
3. Disable scrabling
4. Check local cable
ip address a.b.c.d. 255.255.255.252
no ip redirects
no ip proxy-arp
no peer neighbor-route
dsu bandwidth 44210
serial restart-delay 0
no cdp enable