Proxy server or redirect server?


We have one asterisk server in our head office.Sometimes we face internet problems and our subscribers are unable to make and receive calls so we decided to have one redundant asterisk server in our branch office.So we need a system that can decide which server is alive and it should redirect all invite and register packets to that server which is alive.I first thought heartbeat is the solution but in heartbeat all ips in the cluster have to be in the same network.Then we thought about dns resolution (we have one) but in some devices which we sent to our customers we had to define IP itself.(some systems dont accept char value for the sip server address field).Finally we thought that there should be a server and all requests should be sent to that server and it should route the requests to the alive one.My question is whether I should use proxy server or redirect server for this purpose? I’m really confused cuz it looks like proxy server and sip server are the same things and I couldnt find how to build a redirect server or proxy server itself.Any idea??Any help will be greatly appreciated.

Thanks in Advance.

This looks like a support question, not a general comment!

Isn’t your new server another single point of failure?

You should be able to use Asterisk itelf, either to relay or to redirect (Transfer application).

What are you using as an end point (phone/ATA)?

As I understood it, they have distributed different devices to different customers. I presume what you want to know is the types of all the devices that are restricted to using numeric addresses.

First of all thank you for ur replies.Sorry for opening this topic here.If I should use asterisk itself how should I tell asterisk that it should act like proxy or redirect server?We have different types of end devices like ATA and softphone.Actually all I want to know is how can I set up a system that accepts requests and sends them to the appropriate asterisk server (whether head office or branch office) and which server type to use(proxy or redirect) and how to configure them.

Thanks in Advance

Asterisk can’t act as a proxy server. (It can act as a tandem exchange.)

Terminating a call on the Transfer, rather than Dial application, will make it act as redirect server.

Asterisk can do direct media, i.e. instruct the end points to send RTP directly between themselves, but retain the signalling path, however, as NAT is likely to be involved here, it may be difficult to get the phones to work properly with direct media.

You mean all subscribers should register to the same server but calls must be forwarded to the available server.There will be one asterisk server which subscribers register and the other asterisk servers will act like trunks.Did I understand correct?

With the Transfer application, they will register with one server, it will then send a 302 redirect telling them to make a connection to the working server.

I’ll give it a try.I appreciate ur help.