Can anyone help me understand channel bank timing? I have a server with a Sangoma A104 T1 card connected to two channel banks and I am having audio problems that is clearly timing errors. I thought I understood how to configure it but clearly I don't. All my incoming lines are PSTN, I do not have access to PRI. All my extension phones are SIP. My asterisk version is 1.2.1. Channel bank 1: Adtran 600 with 12 FXO: Timing set to Network on CB /etc/zapata.conf: span=1,0,0,esf,b8zs Channel Bank 2: Adtran 750 with 12 FXO Timing set to loop on channel bank controller span=2,0,0,esf,b8zs With this configuration I am getting choppy sound. What should they be set to? -- Chris Mason NetConcepts (264) 497-5670 Fax: (264) 497-8463 Int: (305) 704-7249 Fax: (815)301-9759 Cell: 264-235-5670 Yahoo IM: netconcepts_anguilla@yahoo.com
> Can anyone help me understand channel bank timing? I have a server with > a Sangoma A104 T1 card connected to two channel banks and I am having > audio problems that is clearly timing errors. I thought I understood how > to configure it but clearly I don't. > All my incoming lines are PSTN, I do not have access to PRI. All my > extension phones are SIP. My asterisk version is 1.2.1. > > Channel bank 1: Adtran 600 with 12 FXO: > Timing set to Network on CB > /etc/zapata.conf: span=1,0,0,esf,b8zs > > > Channel Bank 2: Adtran 750 with 12 FXO > Timing set to loop on channel bank controller > span=2,0,0,esf,b8zs > > With this configuration I am getting choppy sound. What should they be > set to?I don't believe the above config is correct. Pick one of the channel banks and declare it as your source for timing. I'll pick CB1 so as to follow through the words below. Both channel banks will be generating timing/clock signals within their transmit leg towards the asterisk box. That is part of T1/E1 low level protocol design and you can't change it even if you wanted to. On the asterisk T1 port connected to CB1, use: span=1,1,0,esf,b8zs where the second "1" tells your asterisk T1 card to use this port for syncing the onboard T1 clock (on the Sangoma card). On the asterisk T1 port connected to CB2, use: span=2,2,0,esf,b8zs where the second "2" tells your asterisk T1 card to use this port for sync "if" the first port does dead, fails, cable is disconnected, or for any other reason that would essentially represent a failure of CB1. On CB2, configure it to obtain "its" clock sync from the T1. (I don't have any Adtrans around, so can't tell you exactly what the setting words are.) On CB1, configure it to use internal T1 clocking (whatever words those happen to be for an Adtran). If you just want to play around without changing the CB at all, just change the second digit in "span=1,0,0,esf,b8zs" to indicate that its your source for timing. Only one span= statement can have a "1". I'm not 100% sure on this next statement, but would guess you'll need to stop asterisk and reload the T1 card drivers (or simply reboot).
On Sunday 25 December 2005 18:39, Chris Mason (Lists) wrote:> Can anyone help me understand channel bank timing? I have a server with > a Sangoma A104 T1 card connected to two channel banks and I am having > audio problems that is clearly timing errors. I thought I understood how > to configure it but clearly I don't. > All my incoming lines are PSTN, I do not have access to PRI. All my > extension phones are SIP. My asterisk version is 1.2.1.Tell the Channel Banks clock to the line, and have the Sangoma card NOT sync to anything (i.e. the A104 is the master, the channel banks the slaves). Basically clocking works this way: Each end of a T1 sends data generated by an on-board clock. These two clocks (one at each side) needs to be in perfect sync with each other or you get frame slips and other nasties. The solution is to have one of these clocks lock or synchronize to the far side. This is know by several names, among them "line clock", "recovered clock", "slave clock", etc. The side that is not trying to synchronize is also known my several names... "master clock", "internal clock", etc. So it comes down to this: One side must synchronize its clock to the other side (which does NOT do this) or you will have frame slips. The Digium multi-span T1/E1 cards can only slave to one clock for the whole card, whereas the Sangoma cards are a little different and can have each span slave to its own clock. For your particular application it doesn't matter. Have the card provide sync (be the master, internal, etc.) and have the channel banks recover clock (be the slave, use line clock, etc.) from the line. Hopefully that helps. :-)> Channel bank 1: Adtran 600 with 12 FXO: > Timing set to Network on CB > /etc/zapata.conf: span=1,0,0,esf,b8zs > > Channel Bank 2: Adtran 750 with 12 FXO > Timing set to loop on channel bank controller > span=2,0,0,esf,b8zsThat looks perfect. Make sure that you really are setting that. IIRC the Sangoma card needs to have its clock set with the wancfg utility and not just ztcfg. -A.
On Monday 26 December 2005 07:20, Chris Mason (Lists) wrote:> I have always had one working. It was adding the second that caused so > much trouble. > It sounds like dropouts in the speech, short little dropouts..Do you have trouble on *both* when you add the second? What happens if you swap the ports the that channel banks plug in to? Does the problem stick with the span or the channel bank? -A.