Hello! In the near future, I'll be deploying an asterisk system that will have (in addition to many SIP handsets) four FXS handsets. Is there a known limitation to the length of cabling that can be used between a Digium/Openvox/Sangoma FXS card and the end station? I understand the card will need a molex power connector plugged in to provide extra voltage. With traditional phone systems, I have not seen any distance limitations. I would just like to verify that the FXS ports are able to provide sufficient power for longer runs. Thank you!!! Tim Nelson Systems/Network Support Rockbochs Inc.
Kevin P. Fleming
2008-Jan-09 15:47 UTC
[asterisk-users] Zaptel FXS Cards - Station Distance
Tim Nelson wrote:> Hello! In the near future, I'll be deploying an asterisk system that will have (in addition to many SIP handsets) four FXS handsets. Is there a known limitation to the length of cabling that can be used between a Digium/Openvox/Sangoma FXS card and the end station? I understand the card will need a molex power connector plugged in to provide extra voltage. With traditional phone systems, I have not seen any distance limitations. I would just like to verify that the FXS ports are able to provide sufficient power for longer runs. Thank you!!!You don't quote any numbers here, and 'longer' is not anything we can relate to. However, I can say that the FXS line drivers on Digium analog modules should be able to handle 1000' runs or so, but not more than that. This should be equivalent to what any standard PBX with FXS ports can do, unless it has special 'long line' drivers. -- Kevin P. Fleming Director of Software Technologies Digium, Inc. - "The Genuine Asterisk Experience" (TM)
Tilghman Lesher
2008-Jan-09 15:49 UTC
[asterisk-users] Zaptel FXS Cards - Station Distance
On Wednesday 09 January 2008 09:15:08 Tim Nelson wrote:> Hello! In the near future, I'll be deploying an asterisk system that will > have (in addition to many SIP handsets) four FXS handsets. Is there a known > limitation to the length of cabling that can be used between a > Digium/Openvox/Sangoma FXS card and the end station? I understand the card > will need a molex power connector plugged in to provide extra voltage. With > traditional phone systems, I have not seen any distance limitations. I > would just like to verify that the FXS ports are able to provide sufficient > power for longer runs. Thank you!!!There are limitations, even with traditional systems. It's usually around 1,000 feet, but the basic problem is that DC signalling degrades over distance. Incidentally, this is why power lines are provided with AC current. The TDM cards should be able to provide reliable signalling over the same distance as traditional telephony lines, as they are sending with the same power specifications. -- Tilghman