Is it a Verizon circuit? We have a T1 circuit with Verizon and have the same problem. We have a point to point circuit, so one side has clocking set to internal to provide the clocking and the other side feeds from the line. I wrote the problem up at http://ccie-security.blogspot.com/ But basically, it will be up for a some hours then down, then I call them to test and it's good again. Sometime it's good just by unplug the cable and plug it back. Like you, we changed everything and that didn't help. Finally, we talked to a knowledgeable Verizon tester and he mentioned the rate on the line is ~17 which is high. It should be around 0 or negative. He said that's because of mismatch clocking between our hardware and the central office crossover equipment. The normal tester won't look at this, they only do the loopback pattern testing, so you should ask them about the rate of your line. They swapped one smart jack, but that didn't help, so they will swap the other today. Hopefully that will do it. Good information here about troubleshooting T1 http://www.informit.com/library/content.aspx?b=Troubleshooting_Remote_Access &seqNum=61
Luan Nguyen Chesapeake NetCraftsmen, LLC. www.NetCraftsmen.net -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ted Mittelstaedt Sent: Wednesday, October 15, 2008 7:31 AM To: [email protected] Subject: [c-nsp] OK, what is a cheap and dirty hack to test a port Hi All, I have an 8 port PA-8T serial card in a router. The card has an octopus cable that is plugged into a rack of card DSU's. Most of the DSU's have T1's into them. One T1 has developed a problem where it runs for a few hours and then the router serial interface it is on goes down. When it's down, from the carrier side the carrier can issue a loop command to the CSU on the port, and the CSU will loop up, and the carrier can run patterns on it all day long just fine. I have replaced both the 8 port card and the DSU card in the rack on that specific port with no change. If I momentararily flip the loopback switch on the DSU to throw a loop towards the carrier, facing away from the router, when the switch returns the router port enables and the T1 runs for a few more hours just fine. I didn't believe this when I first saw it, but I've done it several times since. I actually don't think the looping has anything to do with anything though - if I pull the DSU card and replace it, the circuit comes back up also. So I went and moved the T1 to another DSU and port on the router and inserted a physical loopback plug into the problem DSU network port. The router port of course sees this as a looped port now. My question, is there a way I can configure the router port so that I can throw a massive amount of (bogus, naturally) traffic to it, and the traffic will go out the port, through the DSU, loopback through the hard loopback plug, then come back into the router and go into the bit bucket? If I simply assign something like IP 127.0.0.5/30 to the port and throw a ton of traffic to 127.0.0.6, will the packets actually go out the port? Or will the router see that the port is looped and just discard the traffic? Ted _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
