Ok, I have a backup frame relay that I can test on. Here's my findings: I have an Excalibur ISX5311 connected to a 7206VXR. We have a full T to the frame using ESF framing. The line is up/up. I modified the framing to D4 (there appears to be no SF?), and checked the line. It went down/down. I was surprised. I expected up/down. It was showing DCD & DTS were down.
I then put my framing back and changed the linecode. We use B8ZS, so I changed to AMI. The line then started flapping up/up to down/down. Again, when in down/down it was showing DCT & DTS down. Anything else I should test? > would somebody just change some settings on an external CSU/DSU and report > the results? Who cares if it's a production network? It's getting towards > midnight, it'll only take a couple of minutes, and the suits are all asleep! > ;-> > > > ""John Neiberger"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > This isn't quite true. For example, a DCE router interface will be > > down/down if DTR is not raised by the DTE device. I see this quite > > often at work and faulty cabling is generally not the culprit. It's > > almost always bad hardware in the DTE. > > > > John > > > > Michael L. Williams wrote: > > > According to CCIE exam materials, the *only* time the serial will show > > > down/down is when there is NO serial cable or a bad serial cable > connected. > > > So even if you have a misconfigured framing method, you should at least > see > > > up/down..... > > > > > > Mike W. > > > > > > "Bob Timmons" wrote in message > > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > > > >>I can't say I've ever seen a down/up condition. Up/Down perhaps. > > >> > > >>I'm sure there are exceptions, but it's my belief that the router > doesn't > > >>care about encoding, but rather a layer-1 connection to the dce/dte > > > > > > device. > > > > > >>If the router can 'talk' to the device on the other end of the cable, > you > > >>should get an up/x condition, where x would depend on the csu/dsu > > > > > > condition > > > > > >>of the line. > > >> > > >>I don't have a csu handy, otherwise I'd check that right now. I can do > > > > > > that > > > > > >>tomorrow morning (10:30 pm est here), but you may have an answer prior > to > > >>that... > > >> > > >> > > >> > > >>>Hi Priscilla, > > >>> > > >>>I have actually had this scenario (multiple times), but due to the > > >> > > > Telco's > > > > > >>>misconfiguration. > > >>>Specifically we were expecting b8zs/esf. Unfortunately I can't confirm > > >>>which was configured incorrectly, but I can confirm that going through > > >>>all of the different combinations available at the router you will > > >>>get all combinations on the serial interface (up/up, down/up and > > >> > > >>down/down). > > >> > > >>>I can also confirm, you will not establish connectivity, regardless. I > > >>>believe > > >>>either b8zs/esf or sf/ami are the only valid combinations. At least > that > > >> > > >>is > > >> > > >>>all I've > > >>>ever worked with. > > >>> > > >>>Hope this helps, > > >>>-TV > > >>> > > >>> > > >>>""Priscilla Oppenheimer"" wrote in message > > >>>[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > >>> > > >>>>Hi Group Study, > > >>>> > > >>>>While writing some questions for a practice test, I found myself > > >>>>questioning what I thought was the right answer. Here's the scenario: > > >>>> > > >>>>A Cisco router serial interface is correctly connected with a good > > >>> > > > V.35 > > > > > >>>>cable to the data port on the DSU side of a CSU/DSU. The CSU/DSU has > > >>> > > >>been > > >> > > >>>>misconfigured for the framing method (SF instead of ESF). The framing > > >>>>doesn't match what the provider is using. (The question refers to a > > >>> > > >>>CSU/DSU > > >>> > > >>>>that is external to the router, not one that is built into the > > >>> > > > router.) > > > > > >>>>Will the Cisco router serial interface be down/down or up/down? > > >>>> > > >>>>And, would the answer be any different if the question has to do with > > >>>>misconfiguring the encoding (AMI versus B8ZS)? > > >>>> > > >>>>If you have real-world experience with this, that would help. I have > > >>> > > >>read > > >> > > >>>>the Cisco documentation and the troubleshooting charts, etc. > > >>>> > > >>>>Thanks > > >>>> > > >>>>Priscilla > > >>>> > > >>>>________________________ > > >>>> > > >>>>Priscilla Oppenheimer > > >>>>http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=47131&t=47101 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
