Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
On 04/25/06 05:58 Sangoma Techdesk said the following: At Sangoma we do quite a lot of back-to back T1 and E1 connections. T1 is not a very fussy connection, as the baud rate is only about 750 kbps. In our experience, for error free communications you can use the following rules of thumb: Up to 50 ft: Flat patch cable Up to 500 ft: Ordinary twisted telephone cable Cat 5 may be overkill unless you are going hundreds of feet. we've faced weird intermittent problems and we suspect it's related to electrical interference caused by power cables et al in the server rack. we've seen this with both sangoma and digium cards when attempting to connect asterisk boxes to carrier E1s provided by the local operator. the cables used are normal cat5 UTP cables. -- Regards, /\_/\ All dogs go to heaven. [EMAIL PROTECTED](0 0)http://www.alphaque.com/ +==oOO--(_)--OOo==+ | for a in past present future; do| | for b in clients employers associates relatives neighbours pets; do | | echo The opinions here in no way reflect the opinions of my $a $b. | | done; done | +=+ ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Shielding of T1/E1 cables WAS RE: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Also note that the Smart Jack allows the Telco to provide T1 Signalling in places that it couldn't in the past, most smart jacks that I have used are: [CO]-Optical-[Hut DMS]--[Hut Smart Jack]-HDSL-[CPE Smart Jack] For the list, Telco Techs, mostly do as they are told, and are schooled by the Telco vendors. On 4/24/06, Rich Adamson [EMAIL PROTECTED] wrote: Alexander Lopez wrote: I was once told by a lineman that the cables they use didn't have that many twists in them because it wasn't needed, and that the extra twists would effectively use more cable and thus cost and weigh more than triple what they do now. Good thing he doesn't work for a cable manufacturer as that's a total crock of crap that even an inexperienced person should be able to detect. (You can't twist two wires to make them weight three times as much, or cost three times as much.) He told me that with the number of twists in the Cat 5 cable it would cancel out any interference, but he also stated that the effective length was calculated using a cable with less twists and subsequently 'less dense' and that if using a Cat5e cable you must factor that in. so if you use cat5e cable your are fine but you can't go as far. Essentially true, but the impedance of a T1 cable is different from Cat5 cables, which is one of the primary factors in limiting distance. Has nothing to do with the twists. Shielded vs non-shielded has to do with the environment, and how much electrical noise there is near the T1 cable. Nothing more, nothing less. Regarding the Smart Jack it is mostly used as a location at the CPE where the Telco can loop and make sure that the problem is at your end. So your assumption is correct that you can plug anything you want into it, its one your side of the demark, so if it doesn't work it's YOUR problem. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users -- --- Andrew Latham - AKA: LATHAMA (lay-th-ham-eh) [EMAIL PROTECTED] - [EMAIL PROTECTED] - [EMAIL PROTECTED] If any of the above are down we have bigger problems than my email! Hind sight is most always 20/20 or better. --- ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Can't anyone stop self-promotion and tell the poor guy what he needs. A T1/E1 X-over cable using an RJ-45 (8-cond.) is pinned out as follows: 1 - 4 2 - 5 3 - NU 4 - 1 5 - 2 6 - NU 7 - NU 8 - NU NU = Not Used I have not in my experience seen any problems with using a Good Quality Cat5 vs. Cat 3 (telco standard) cable for X-connects. YMMV, but you should be fine. As far as the shielding goes, I use UTP cables and Connectors all the time and some of my X-connects run over 100 feet. It would probably be helpful for everyone reading this thread to understand what the differences are in the two types of cables. Primarily impedance matching, twists per foot, shielding, etc. For short runs, the use of cat5 vs proper T1 cables isn't likely to have any impact unless there is a fair amount of induction from electrical noise, etc. That can take the form of florescent fixtures, transformers, older CRT monitors, etc, etc. On longer runs, the shielded T1 cables are likely to provide better results particularly if there happens to be any electrical noise. Oh, and if shielded T1 cable is used, the shield at each end of the cable must be grounded. (Let's see how many can figure out how to do that via an rj45 plug. ;) ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Rich Adamson wrote: snip For short runs, the use of cat5 vs proper T1 cables isn't likely to have any impact unless there is a fair amount of induction from electrical noise, etc. That can take the form of florescent fixtures, transformers, older CRT monitors, etc, etc. On longer runs, the shielded T1 cables are likely to provide better results particularly if there happens to be any electrical noise. Oh, and if shielded T1 cable is used, the shield at each end of the cable must be grounded. (Let's see how many can figure out how to do that via an rj45 plug. ;) Totally agree with you, unshielded cables are only usable if the distance is short. Just curious, how should one ground the shield? Do you ground it to the ground bar in the server room? Any special requirements? TIA ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Leo Ann Boon wrote: Rich Adamson wrote: snip For short runs, the use of cat5 vs proper T1 cables isn't likely to have any impact unless there is a fair amount of induction from electrical noise, etc. That can take the form of florescent fixtures, transformers, older CRT monitors, etc, etc. On longer runs, the shielded T1 cables are likely to provide better results particularly if there happens to be any electrical noise. Oh, and if shielded T1 cable is used, the shield at each end of the cable must be grounded. (Let's see how many can figure out how to do that via an rj45 plug. ;) Totally agree with you, unshielded cables are only usable if the distance is short. Just curious, how should one ground the shield? Do you ground it to the ground bar in the server room? Any special requirements? That would be one way to do it, at both ends. Personally, I would not try to install an rj45 on each end of a shielded T1 cable, but rather terminate the cable on a patch panel. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: Shielding of T1/E1 cables WAS RE: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
I was once told by a lineman that the cables they use didn't have that many twists in them because it wasn't needed, and that the extra twists would effectively use more cable and thus cost and weigh more than triple what they do now. He told me that with the number of twists in the Cat 5 cable it would cancel out any interference, but he also stated that the effective length was calculated using a cable with less twists and subsequently 'less dense' and that if using a Cat5e cable you must factor that in. so if you use cat5e cable your are fine but you can't go as far. Regarding the Smart Jack it is mostly used as a location at the CPE where the Telco can loop and make sure that the problem is at your end. So your assumption is correct that you can plug anything you want into it, its one your side of the demark, so if it doesn't work it's YOUR problem. Totally agree with you, unshielded cables are only usable if the distance is short. Just curious, how should one ground the shield? Do you ground it to the ground bar in the server room? Any special requirements? That would be one way to do it, at both ends. Personally, I would not try to install an rj45 on each end of a shielded T1 cable, but rather terminate the cable on a patch panel. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: Shielding of T1/E1 cables WAS RE: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
My telco used cat5 as well for the demarc to CPE. It's also with noting that many channel banks, such as my Atlas, and zapata.conf itself also have parameters to allow you to tune the gains to compensate for cable signal loss. I've never had to touch them, and my CPE is about 300 feet from the PRI demarc (with an ordinary Cat5 cable connecting them) ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Shielding of T1/E1 cables WAS RE: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Alexander Lopez wrote: I was once told by a lineman that the cables they use didn't have that many twists in them because it wasn't needed, and that the extra twists would effectively use more cable and thus cost and weigh more than triple what they do now. Good thing he doesn't work for a cable manufacturer as that's a total crock of crap that even an inexperienced person should be able to detect. (You can't twist two wires to make them weight three times as much, or cost three times as much.) He told me that with the number of twists in the Cat 5 cable it would cancel out any interference, but he also stated that the effective length was calculated using a cable with less twists and subsequently 'less dense' and that if using a Cat5e cable you must factor that in. so if you use cat5e cable your are fine but you can't go as far. Essentially true, but the impedance of a T1 cable is different from Cat5 cables, which is one of the primary factors in limiting distance. Has nothing to do with the twists. Shielded vs non-shielded has to do with the environment, and how much electrical noise there is near the T1 cable. Nothing more, nothing less. Regarding the Smart Jack it is mostly used as a location at the CPE where the Telco can loop and make sure that the problem is at your end. So your assumption is correct that you can plug anything you want into it, its one your side of the demark, so if it doesn't work it's YOUR problem. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Shielding of T1/E1 cables WAS RE: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
On Mon, 24 Apr 2006, Rich Adamson wrote: Alexander Lopez wrote: I was once told by a lineman that the cables they use didn't have that many twists in them because it wasn't needed, and that the extra twists would effectively use more cable and thus cost and weigh more than triple what they do now. Good thing he doesn't work for a cable manufacturer as that's a total crock of crap that even an inexperienced person should be able to detect. (You can't twist two wires to make them weight three times as much, or cost three times as much.) A foot of cat5 has more than 12 on each of the individual wires inside. Not much but there is some difference. -- Dave Weis I believe there are more instances of the abridgment [EMAIL PROTECTED] of the freedom of the people by gradual and silent encroachments of those in power than by violent and sudden usurpations.- James Madison ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Rich Adamson wrote: Oh, and if shielded T1 cable is used, the shield at each end of the cable must be grounded. (Let's see how many can figure out how to do that via an rj45 plug. ;) You use shielded plugs and jacks, of course :-) That is why the TE405P/TE410P have shielded jacks (as of about a year ago, IIRC). The retail packaged cards even ship with four shielded cables included! Minor point: isn't it safer to only ground the shield on one end? ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
On Monday 24 April 2006 12:13, Kevin P. Fleming wrote: Minor point: isn't it safer to only ground the shield on one end? Yes, you *never* shield both ends. That can cause ground loops and add to the long list of what the..? head-scratching problems that telephony has. As to WHICH end to ground... well that's a subject that holy wars have been started over... -A. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Kevin P. Fleming wrote: Rich Adamson wrote: Oh, and if shielded T1 cable is used, the shield at each end of the cable must be grounded. (Let's see how many can figure out how to do that via an rj45 plug. ;) You use shielded plugs and jacks, of course :-) That is why the TE405P/TE410P have shielded jacks (as of about a year ago, IIRC). The retail packaged cards even ship with four shielded cables included! Excellent! Minor point: isn't it safer to only ground the shield on one end? Best practices suggests IT/telco equipment racks throughout a building share a single grounding system (and not with 24 ga cable). Likewise, grounding of both ends of a T1 (eg, shield) is considered best practice. Treat a T1 cable as no different then a transmission line with a 1.5mhz RF signal. If rack grounding is totally ignored (which probably happens frequently), there is a possibility of a ground loop created through the T1 shield. But, the root-cause is the lack of rack grounding, not leaving one end of a T1 cable ungrounded. For safety, also think about the number of devices that are produced with poor power supplies, hot chassis, etc. Seen (and felt) several of those. ;) R. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
At Sangoma we do quite a lot of back-to back T1 and E1 connections. T1 is not a very fussy connection, as the baud rate is only about 750 kbps. In our experience, for error free communications you can use the following rules of thumb: Up to 50 ft: Flat patch cable Up to 500 ft: Ordinary twisted telephone cable Cat 5 may be overkill unless you are going hundreds of feet. David Yat Sin Sangoma Technologies (905) 474 1990 x119 (800) 388 2475 x199 MSN: [EMAIL PROTECTED] Email: [EMAIL PROTECTED] Wiki: http://sangoma.editme.com Date: Mon, 24 Apr 2006 20:19:02 +0800 From: Leo Ann Boon [EMAIL PROTECTED] Subject: Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ? To: [EMAIL PROTECTED],Asterisk Users Mailing List - Non-Commercial Discussion asterisk-users@lists.digium.com Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=ISO-8859-1; format=flowed Rich Adamson wrote: snip For short runs, the use of cat5 vs proper T1 cables isn't likely to have any impact unless there is a fair amount of induction from electrical noise, etc. That can take the form of florescent fixtures, transformers, older CRT monitors, etc, etc. On longer runs, the shielded T1 cables are likely to provide better results particularly if there happens to be any electrical noise. Oh, and if shielded T1 cable is used, the shield at each end of the cable must be grounded. (Let's see how many can figure out how to do that via an rj45 plug. ;) Totally agree with you, unshielded cables are only usable if the distance is short. Just curious, how should one ground the shield? Do you ground it to the ground bar in the server room? Any special requirements? TIA ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Hello, The pinout is like 1,2,4,5 you need to use LED and check the signal, connect the telco send with your receive, your receive wth the telco send. you need to be sure about some parametres, the line code (HDB3 or other, the CRC4 is on or off, the impedance 75 or 120 if you are using CAT5 you need to configure 120 ohm. the best way is to test all parametres if you don't now your telco's parametres. Best Regards, On 4/22/06, Steve Totaro [EMAIL PROTECTED] wrote: LOL-Original Message-From: Paul Mahler [mailto: [EMAIL PROTECTED]]Sent: Sat 4/22/2006 11:09 AMTo: asterisk-users@lists.digium.comCc:Subject:Re: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ? A T carrier cable is not the same as an ethernet cable. A T carriercable uses a real metal shielded RJ-45 and loosely twisted pair wire.With most modern T carrier equipment, you can use a CAT-5 ethernet cableinstead of a real T carrier cable. A T-carrier crossover cable does nothave the same wiring pattern as a crossover ethernet cable. With anolder piece of equipment like the Matra, I would be tempted to purchasea real T carrier crossover cable. This is covered in my book, by the way. Louis-David Mitterrand wrote:Hello,I am about to put an asterisk server between the telco E1 and our oldMatra PBX.Should I use an ethernet cross cable? Something else? Paul [EMAIL PROTECTED]www.signate.com___--Bandwidth and Colocation provided by Easynews.com --Asterisk-Users mailing listTo UNSUBSCRIBE or update options visit:http://lists.digium.com/mailman/listinfo/asterisk-users ___--Bandwidth and Colocation provided by Easynews.com --Asterisk-Users mailing listTo UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
A T carrier cable is not the same as an ethernet cable. A T carrier cable uses a real metal shielded RJ-45 and loosely twisted pair wire. With most modern T carrier equipment, you can use a CAT-5 ethernet cable instead of a real T carrier cable. A T-carrier crossover cable does not have the same wiring pattern as a crossover ethernet cable. With an older piece of equipment like the Matra, I would be tempted to purchase a real T carrier crossover cable. This is covered in my book, by the way. Louis-David Mitterrand wrote: Hello, I am about to put an asterisk server between the telco E1 and our old Matra PBX. Should I use an ethernet cross cable? Something else? Paul [EMAIL PROTECTED] www.signate.com ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
LOL -Original Message- From: Paul Mahler [mailto:[EMAIL PROTECTED] Sent: Sat 4/22/2006 11:09 AM To: asterisk-users@lists.digium.com Cc: Subject:Re: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ? A T carrier cable is not the same as an ethernet cable. A T carrier cable uses a real metal shielded RJ-45 and loosely twisted pair wire. With most modern T carrier equipment, you can use a CAT-5 ethernet cable instead of a real T carrier cable. A T-carrier crossover cable does not have the same wiring pattern as a crossover ethernet cable. With an older piece of equipment like the Matra, I would be tempted to purchase a real T carrier crossover cable. This is covered in my book, by the way. Louis-David Mitterrand wrote: Hello, I am about to put an asterisk server between the telco E1 and our old Matra PBX. Should I use an ethernet cross cable? Something else? Paul [EMAIL PROTECTED] www.signate.com ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users winmail.dat___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Can't anyone stop self-promotion and tell the poor guy what he needs. A T1/E1 X-over cable using an RJ-45 (8-cond.) is pinned out as follows: 1 - 4 2 - 5 3 - NU 4 - 1 5 - 2 6 - NU 7 - NU 8 - NU NU = Not Used I have not in my experience seen any problems with using a Good Quality Cat5 vs. Cat 3 (telco standard) cable for X-connects. YMMV, but you should be fine. As far as the shielding goes, I use UTP cables and Connectors all the time and some of my X-connects run over 100 feet. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Steve Totaro Sent: Saturday, April 22, 2006 11:49 AM To: Paul Mahler; Asterisk Users Mailing List - Non-Commercial Discussion Subject: RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ? LOL -Original Message- From: Paul Mahler [mailto:[EMAIL PROTECTED] Sent: Sat 4/22/2006 11:09 AM To: asterisk-users@lists.digium.com Cc: Subject:Re: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ? A T carrier cable is not the same as an ethernet cable. A T carrier cable uses a real metal shielded RJ-45 and loosely twisted pair wire. With most modern T carrier equipment, you can use a CAT-5 ethernet cable instead of a real T carrier cable. A T-carrier crossover cable does not have the same wiring pattern as a crossover ethernet cable. With an older piece of equipment like the Matra, I would be tempted to purchase a real T carrier crossover cable. This is covered in my book, by the way. Louis-David Mitterrand wrote: Hello, I am about to put an asterisk server between the telco E1 and our old Matra PBX. Should I use an ethernet cross cable? Something else? Paul [EMAIL PROTECTED] www.signate.com ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Alexander Lopez wrote: Can't anyone stop self-promotion and tell the poor guy what he needs. Seems to me that SOME self promotion belongs on the biz list, and for those considered in the inner circle it is OK here! Everyone is equal. Some are more equal than others JMO John Novack ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: Pinouts for T1/E1 crossover cable WAS RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?
Alexander Lopez wrote: I have not in my experience seen any problems with using a Good Quality Cat5 vs. Cat 3 (telco standard) cable for X-connects. YMMV, but you should be fine. As far as the shielding goes, I use UTP cables and Connectors all the time and some of my X-connects run over 100 feet I have used cat-5 for everything communications. serial printers, dumb terminals, DS1 and even 10/100 ethernet. :-) It's easier to have it installed as a network jack and then use for whatever you need. ... Andrew McRory LinuxSystems Tallahasse, FL ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
