[Asterisk-Dev] Question about E1 Card / ISDN PRI

[Vinod Sankar]

Thanks ! 

Vinod

On Sat, Mar 22, 2003 at 09:12:20AM +0800, Leo Ann Boon wrote:
- Some answers:
- 1. ISDN PRI is usually from your telco to you. It's normally used to 
- replace analog lines. 1 E1 PRI is equivalent to 30 analog lines, so you 
- can imagine the savings in wiring. But, you can't directly plug a phone 
- to an E1 PRI, it has to be splitted up using a PBX (like the *).
- 
- 2. You'll have to use CCS (Common Channel Signaling) or more commonly 
- known as D-Channel signaling. Excerpts from my zaptel.conf for an E100P:
- span=1,0,0,ccs,hdb3,crc4
- bchan=1-15
- dchan=16
- bchan=17-31
- 
- The dchan is a must for PRI, it tells the E100P to use channel 16 for 
- signaling instead of voice. The crc4 option is usually required for E1 
- PRI, but if check with your telco. I've seen some E1 PRIs supplied 
- without crc4 (no thanks to DMS100).
- 
- 3. I don't think S/T or U applies to PRI, it's for BRI. Perhaps someone 
- else can explain this better.
- 
- 4. R2MF is an E1 CAS (Channel Associated Signaling), it's like T1 
- robbed-bit signaling. PRI is CCS.  IIRC, the zaptel supports R2 
- signaling for China.
- 
- Help this helps.
- 
- Vinod Sankar wrote:
- 
- >I have a few basic questions. Apologies in advance if this is
- >the wrong forum for what should be a Digium FAQ.
- >
- >I'm trying to use the Digium E1 card to provide an IP PBX like 
- >application to an enterprise that needs about 30 telephone lines, 
- >in India. India supports R2MF and ISDN PRI (Euro ISDN) signaling
- >standards. The Digium card supports only ISDN PRI. 
- >
- >The questions are, 
- >
- >	- Are ISDN PRI lines used only for branch to branch 
- >(closed group) calling, where the PSTN is unaware of how the 
- >channels are used (Voice/Data) or can PSTN switches terminate 
- >voice calls from public analog phones into this ISDN PRI circuit ?
- >
- >	- The Zaptel configuration mentions framing options for defining
- >spans for E1 lines as either CCS or CAS. Do I specify CCS for an
- >E1 ISDN PRI line from PSTN terminating on this card ?
- >
- >	- What interface does Digium E1 card support S/T or U ?
- >
- >Also, quickly, what is the difference between R2MF and ISDN PRI ?
- >If someone could point me to a website that has more info on these
- >subjects, that would be great.
- >
- >thanks,
- >Vinod Sankar
- >_______________________________________________
- >Asterisk-Dev mailing list
- >Asterisk-Dev at lists.digium.com
- >http://lists.digium.com/mailman/listinfo/asterisk-dev
- >
- >  
- >
- 
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