Hi List, After reading a bunch of the docs, list post archives, it still seems that a clear definition of how to clock the T100P card is muddy. zttool says that the link is "INTERNALLY CLOCKED", does this mean the T100P is providing clock, or does this mean the T100P is getting clock from the T1 line side (ergo getting clock from the Telco) ?? If you have sync = 0 then zttool says internally clocked if sync > 0 then zttool says "Digium......." and link goes into an error condition. Thus the million dollar question is this: What should the SYNC value be if you want to clock from the TELCO ? Maybe zttool is reporting things in error ?? thanks mucho
On Sunday, January 11, 2004 5:41 PM, John Brown (CV) [SMTP:jmbrown@chagresventures.com] wrote:> Hi List, > > After reading a bunch of the docs, list post archives, it > still seems that a clear definition of how to clock the T100P > card is muddy. > > zttool says that the link is "INTERNALLY CLOCKED", > > does this mean the T100P is providing clock, or does > this mean the T100P is getting clock from the T1 line > side (ergo getting clock from the Telco) ?? >This was really confusing for me when I started. Let me explain it this way. If you want to run on the internal T100P clock then set sync to '0' To derive the timing from the incoming T1 line (loop timing) set sync to '1'> > If you have sync = 0 then zttool says internally clocked > > if sync > 0 then zttool says "Digium......." and link > goes into an error condition.I don't know what this would be.> > Thus the million dollar question is this: > > What should the SYNC value be if you want to clock from > the TELCO ?sync should be set to 1 to time from telco.> > Maybe zttool is reporting things in error ?? > > thanks mucho-- Don Pobanz
On Tuesday, January 13, 2004 7:36 AM, Andrew Kohlsmith [SMTP:akohlsmith-asterisk@benshaw.com] wrote:> > If you've got spans from different providers...you're in for an > > adventure. You'll be able to do one of the following (which one is > > telco > > and luck dependant):If all providers are referenced back to a stratum 1 clock (which they should be) then all provider spans should have very very very close timing. Close enough that only a few frame slips a year may occur. So, in general spans from different providers should not be a problem.> > So what you're saying is that the TE410P is not capable of > *independently* > clocking each of the T1s. Hell even the venerable old AS5248 can > handle > that. This is going to be fun...That is correct.> > Is it possible to accept clock from the telco for one span and > *generate* > clock on the other three spans (i.e. for internal channel banks and > whatnot) ? Will I run into problems there? I don't forsee it but I > also > didn't forsee the problem being discussed in this thread...Yes it is possible to receive clock from one span and provide it for the other three. That is how I am running.> > Regards, > AndrewDon Pobanz
> > If you've got spans from different providers...you're in for an > > adventure. You'll be able to do one of the following (which one is telco > > and luck dependant): > > So what you're saying is that the TE410P is not capable of *independently* > clocking each of the T1s. Hell even the venerable old AS5248 can handle > that. This is going to be fun...Dont think they do.. on the controllers you specify clock source primary/secondary and the box will sync to only one clock. This is true in all telco systems afaik.. taking lines from another telco which is on a different clock source isnt necessarily a big problem but you should expect to see the odd slips on the line where the clocking is slightly mismatched.. Steve
On Wednesday, January 14, 2004 11:41 AM, TC [SMTP:trclark@shaw.ca] wrote:> What are the practical effects with in-correct clock sync > -like to you hear odd buzzing, or dropped voice or gaps of audio ?? >It depends on how out of sync the clocks are and the type of signaling being used. For a T1 with robbed bit signaling you would just hear a click or pop on the line. If the clocks are close this may just occur a few times a day. If there is more difference in the clocks it could happen every few minutes or more. For PRI ISDN it may drop the calls or not allow a call to be set up. There have been some in the past who have had problems getting PRI ISDN to stay up and it was due to clocking. Don Pobanz
Stephen Davies wrote:>On Wed, 14 Jan 2004, TC wrote: > > > >>What are the practical effects with in-correct clock sync >>-like to you hear odd buzzing, or dropped voice or gaps of audio ?? >> >> > >Old-fart anecdote about this - in the early 80s we had some 1200bps >modems that we used to connect to client sites. When our phone >company went digital we suddenly started getting a } character at a >regular interval of 10 or 15 seconds. > >This turned out to be clock slips in the new digital trunk between the >two exchanges. > >So there is one effect of clock slips. > >Steve > >That must have been an FSK modem. Most advanced modems completely loose sync on the first sample slip. The sample slip causes a jump in phase, and phase is critical to the correct operation of most modems. Regards, Steve
On Wed, 14 Jan 2004, Steve Underwood wrote:> That must have been an FSK modem. Most advanced modems completely loose > sync on the first sample slip. The sample slip causes a jump in phase, > and phase is critical to the correct operation of most modems.It was V.22. No error correction or anything new-fangled like that. (Not auto dial either). Steve