Posted: Fri Mar 21, 2003 1:08 pm Post subject: [Asterisk-Dev] Question about E1 Card / ISDN PRI
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.
Posted: Sat Mar 22, 2003 1:12 am Post subject: [Asterisk-Dev] Question about E1 Card / ISDN PRI
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:
Quote:
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.
Posted: Fri Mar 28, 2003 5:25 am Post subject: [Asterisk-Dev] Question about E1 Card / ISDN PRI
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@lists.digium.com
- >http://lists.digium.com/mailman/listinfo/asterisk-dev
- >
- >
- >
-
- _______________________________________________
- Asterisk-Dev mailing list
- Asterisk-Dev@lists.digium.com
- http://lists.digium.com/mailman/listinfo/asterisk-dev
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum