Warning ! I know zip about electronics. I've been looking for a device to handle the switching of an E1 connection from one Asterisk box to another in the event of a catastrophic server failure. All of the solutions I've seen so far have been designed to handle the situation where the telco line faults so that the local PBX can switch to a secondary E1. I've come across this application note : http://www.maxim-ic.com/appnotes.cfm/appnote_number/2857 which describes "T1/E1/J1, N+1 Redundancy With Analog Switches" These parts are obviously designed to be built into E1 boards - hence, I think, the protection circuitry. Here's the question, then : what (apart from jumping through regulatory hoops) is to stop a simple array of MOSFETS (and a bit of control circuitry) implementing a failover switch controlled (say) by a pin on a serial or parallel port ? jd -- John Daragon john@argv.co.uk argv[0] limited Lambs Lawn Cottage, Staple Fitzpaine, Taunton, TA3 5SL, UK v +44 (0) 1460 234068 f +44 (0) 1460 234069 m +44 (0) 7836 576127
http://www.junghanns.net/en/ISDNguard_produkt.html srsergio -----Mensaje original----- De: John Daragon [mailto:john@argv.co.uk] Enviado el: jueves, 20 de octubre de 2005 17:24 Para: Asterisk Users Mailing List - Non-Commercial Discussion Asunto: [Asterisk-Users] E1/T1 failover hardware Warning ! I know zip about electronics. I've been looking for a device to handle the switching of an E1 connection from one Asterisk box to another in the event of a catastrophic server failure. All of the solutions I've seen so far have been designed to handle the situation where the telco line faults so that the local PBX can switch to a secondary E1. I've come across this application note : http://www.maxim-ic.com/appnotes.cfm/appnote_number/2857 which describes "T1/E1/J1, N+1 Redundancy With Analog Switches" These parts are obviously designed to be built into E1 boards - hence, I think, the protection circuitry. Here's the question, then : what (apart from jumping through regulatory hoops) is to stop a simple array of MOSFETS (and a bit of control circuitry) implementing a failover switch controlled (say) by a pin on a serial or parallel port ? jd -- John Daragon john@argv.co.uk argv[0] limited Lambs Lawn Cottage, Staple Fitzpaine, Taunton, TA3 5SL, UK v +44 (0) 1460 234068 f +44 (0) 1460 234069 m +44 (0) 7836 576127 _______________________________________________ --Bandwidth and Colocation sponsored by Easynews.com -- Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.12.4/143 - Release Date: 19/10/2005
> Warning ! I know zip about electronics.why not just use a multipole relay ? a 4pole double throw relay gives you 4 sets of contacts for the 2x tx and 2x rx wires. if you want to control with a bit in a parallel port, use something like a uln2003 relay driver (if the coil current is low enough), or a couple discrete transistors with the right gain and power handling. use the 12vdc out of a spare drive connector to power the relay. I would use one relay rather than 2 dpdt ones so that the switches are mechanically locked together and if one relay sticks you don't get a weird combination of circuits connected. Nothing will break, and the phone cops won't likely bother you if this does happen, but it could be real annoying and hard to diagnose if it does. This is basically the electromechanical equivalent of you pulling one cable and plugging in another (which is what I was going to do with some T1 routers), except, I found the TXPort. This actually is meant for failing between telco circuits, but works just fine working failing between CPE instead. it actually has csus, reframers, clock generator etc, as well as the "relay" circuit I describe to do the switchover. it actually samples the lines and uses some intelligence to see which to switch to. The device is "obsolete" so you'll only find it surplus now, and its t1 only as far as I know but there is probably E1 gear around that does the same thing. I bought mine for $20 so it was not even worth thinking about my own setup for that price, but they were listed at up to $3000 when new.> > I've been looking for a device to handle the switching of an E1 > connection from one Asterisk box to another in the event of a > catastrophic server failure. All of the solutions I've seen so far have > been designed to handle the situation where the telco line faults so > that the local PBX can switch to a secondary E1. > > I've come across this application note : > > http://www.maxim-ic.com/appnotes.cfm/appnote_number/2857 > > which describes "T1/E1/J1, N+1 Redundancy With Analog Switches" > > These parts are obviously designed to be built into E1 boards - hence, I > think, the protection circuitry. > > Here's the question, then : what (apart from jumping through regulatory > hoops) is to stop a simple array of MOSFETS (and a bit of control > circuitry) implementing a failover switch controlled (say) by a pin on a > serial or parallel port ? > > jd > > -- > > John Daragon john@argv.co.uk > argv[0] limited > Lambs Lawn Cottage, Staple Fitzpaine, Taunton, TA3 5SL, UK > v +44 (0) 1460 234068 f +44 (0) 1460 234069 m +44 (0) 7836 576127 > > > _______________________________________________ > --Bandwidth and Colocation sponsored by Easynews.com -- > > Asterisk-Users mailing list > Asterisk-Users@lists.digium.com > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users >Jon Pounder _/_/_/ _/ _/ _/ _/_/_/ _/ _/ _/_/_/_/ _/ _/_/ _/ _/ _/ _/_/ _/ _/_/ _/ _/ _/_/ _/ _/ _/ _/_/ _/ _/_/_/ _/ _/ _/_/_/_/ _/_/_/ _/ _/ _/_/_/_/ Inline Internet Systems Inc. Thorold, Ontario, Canada Tools to Power Your e-Business Solutions www.inline.net www.ihtml.com www.ihtmlmerchant.com www.opayc.com
Sergio Serrano wrote:> http://www.junghanns.net/en/ISDNguard_produkt.html > > > srsergio > > -----Mensaje original----- > De: John Daragon [mailto:john@argv.co.uk] > Enviado el: jueves, 20 de octubre de 2005 17:24 > Para: Asterisk Users Mailing List - Non-Commercial Discussion > Asunto: [Asterisk-Users] E1/T1 failover hardware > > Warning ! I know zip about electronics. > > I've been looking for a device to handle the switching of an E1 connection > from one Asterisk box to another in the event of a catastrophic server > failure. All of the solutions I've seen so far have been designed to handle > the situation where the telco line faults so that the local PBX can switch > to a secondary E1.Thanks Sergio. I won't need to get the soldering iron out after all. jd -- John Daragon john@argv.co.uk argv[0] limited v +44 (0) 1460 234068 f +44 (0) 1460 234069 m +44 (0) 7836 576127
We use the following device for Asterisk fail-over and our T1s. I believe they have an E1 version also: http://www.red-fone.com/fonebridge.html On Thu, 2005-10-20 at 11:23, John Daragon wrote:> Warning ! I know zip about electronics. > > I've been looking for a device to handle the switching of an E1 > connection from one Asterisk box to another in the event of a > catastrophic server failure. All of the solutions I've seen so far have > been designed to handle the situation where the telco line faults so > that the local PBX can switch to a secondary E1. > > I've come across this application note : > > http://www.maxim-ic.com/appnotes.cfm/appnote_number/2857 > > which describes "T1/E1/J1, N+1 Redundancy With Analog Switches" > > These parts are obviously designed to be built into E1 boards - hence, I > think, the protection circuitry. > > Here's the question, then : what (apart from jumping through regulatory > hoops) is to stop a simple array of MOSFETS (and a bit of control > circuitry) implementing a failover switch controlled (say) by a pin on a > serial or parallel port ? > > jd