Hey guys, Looking for some suggestions here on hardware to use. We have several business customers wanting to start using our VoIP service. We will be replacing their 10 year old Panisonic system with Cisco 7940 phones and a T1. Problem is, they have to keep 1 POTS line for directory listing and 911 emergency failover. I would like suggestions on how to accomplish this. Our asterisk cluster is downtown so we can do the T1 between us and them easily. However, the FX911 is the big problem. Lets say that the T1 line goes down and someone tries to dial 911. Normally the call would go over the T1 down to asterisk cluster and go out over PRI or an FX card. But if the T1 is down, you can't do that. So, the POTS line needs to be plugged into something at the customer site. There are a few Cisco routers that will accept both the T1 and the FX but we can't intercept a SIP call at the router. Right now, the only solution we can think of is putting an asterisk box at their location with an FX card. That way if the T1 goes down, they can still dial intra-office and dial 911 out the FX card. Other suggestions are wide-arms-openly welcome. -Matthew
Matthew Boehm wrote:>Hey guys, > Looking for some suggestions here on hardware to use. We have several >business customers wanting to start using our VoIP service. We will be >replacing their 10 year old Panisonic system with Cisco 7940 phones and a >T1. Problem is, they have to keep 1 POTS line for directory listing and 911 >emergency failover. > I would like suggestions on how to accomplish this. Our asterisk cluster >is downtown so we can do the T1 between us and them easily. However, the >FX911 is the big problem. Lets say that the T1 line goes down and someone >tries to dial 911. Normally the call would go over the T1 down to asterisk >cluster and go out over PRI or an FX card. But if the T1 is down, you can't >do that. So, the POTS line needs to be plugged into something at the >customer site. > >How about getting a cheap 1-port FXO gateway and setting that to be the secondary SIP gateway on all the phones? I'm pretty sure you can do that with the Ciscos. The other possibility, if their office isn't too large, is just to find a big red POTS phone and hook it up to the line.> There are a few Cisco routers that will accept both the T1 and the FX but >we can't intercept a SIP call at the router. Right now, the only solution we >can think of is putting an asterisk box at their location with an FX card. >That way if the T1 goes down, they can still dial intra-office and dial 911 >out the FX card. > >That's a valid option as well. Nick
On Fri, 2004-11-26 at 09:42 -0600, Matthew Boehm wrote:> Hey guys, > Looking for some suggestions here on hardware to use. We have several > business customers wanting to start using our VoIP service. We will be > replacing their 10 year old Panisonic system with Cisco 7940 phones and a > T1. Problem is, they have to keep 1 POTS line for directory listing and 911 > emergency failover. > I would like suggestions on how to accomplish this. Our asterisk cluster > is downtown so we can do the T1 between us and them easily. However, the > FX911 is the big problem. Lets say that the T1 line goes down and someone > tries to dial 911. Normally the call would go over the T1 down to asterisk > cluster and go out over PRI or an FX card. But if the T1 is down, you can't > do that. So, the POTS line needs to be plugged into something at the > customer site. > There are a few Cisco routers that will accept both the T1 and the FX but > we can't intercept a SIP call at the router. Right now, the only solution we > can think of is putting an asterisk box at their location with an FX card. > That way if the T1 goes down, they can still dial intra-office and dial 911 > out the FX card. > > Other suggestions are wide-arms-openly welcome.Maybe you should verify that a frac T1 of PSTN wouldn't be a cost effective option. It would eliminate the 911 problem, the directory listing problem, and could allow you to not worry about the analog line. For instance in our market, a point to point T1 loop costs between $250 and $300 plus taxes. A full PRI is only $650 plus taxes. At some point in between I'm sure you might find the sweet spot for your customer that handles the number of calls they need and has a relatively decent cost. -- Steven Critchfield <critch@basesys.com>