I'm reading through CVOICE study guide and just trying to get my head around some of the concepts. Can anyone tell me if I've got this right?
1) If you configure a T1 for or E1 controller with the command "ds0-group" does this inherently imply that you are using CAS signaling on the digital circuit?
2) I'm noticing that all the options for the "signal-type" parameter in the "ds0-group" command (listed below) seem to be signalling types that I would normally associate with analog interfaces. Does this imply that all CAS signaling methods on a T1/E1 are just digital emulations of analog signaling methods or am I thinking about this the wrong way?
e&m-fgb E & M Type II FGB
e&m-fgd E & M Type II FGD
e&m-immediate-start E & M Immediate Start
fgd-eana FGD Exchange Access North American
fgd-os FGD Operator Services
fxs-ground-start FXS Ground Start
fxs-loop-start FXS Loop Start
none Null Signaling for External Call Control
r1-itu R1 ITU
sas-ground-start SAS Ground Start
sas-loop-start SAS Loop Start
3) From my ref book examples of CCS signaling include:
- Proprietary Implementations
- ISDN PRI or BRI (Has its own call control protocol called Q.931)
- QSIG (Only implemented on ISDN PRI interfaces)
- DPNSS (Operates over standard ISDN physical interfaces)
So... The examples I've seen seem to suggest that if you want CCS signaling on a T1/E1 (and I understand it's the modern prefered method) it impies the use of ISDN service from your provider and you configure your T1/E1 as a PRI to match. If I'm undertanding the option right with ISDN PRI you can then choose from several differnet call control protocols including Q.931, QSIG, or in rare circumstances DPNSS??? I presume it would depend on what you're connecting too?
To sum up... a T1 configured as ISDN PRI implies use of CCS and allows you to choose from various digital signaling protocols and lack of ISDN on a T1/E1 implies use of CAS with a choice of older analog protocol emulated digitally. Is that an accurate statement?
Thanks much for any assistance and yes I will rate responses :)