Replacing HiPath 3350 with Asterisk?

Hi all,

Looking for some advice and where better to ask then here…

Currently we are using a Siemens HiPath 3350 and we want to replace it, so I thought it would be a good time to look at VOIP solutions, but am new to it all (VOIP and Asterisk). I do have experience running linux servers, etc. I would like to know if it is possible (of course it is!) to replace our current setup with Asterisk and what I need to get that accomplished.

Here is our current setup:
Siemens HiPath 3350 with several ISDN lines. About 6 wired phones hooked up, 2 dect stations which are connected to about 6 cordless phones. There is also a analog line going from the HiPath to the faxmachine (which in turn is daisy chained to the fax server. the fax server receives the faxes, fax machine is used to send faxes). I am not sure if the fax line is a seperate analog line or if it is using one of the isdn lines.

What would we need to replace that with a Asterisk setup? I would like to retain 1 ISDN line for use of emergencies, in case the internet connection drops out. Which would serve as a backup line for Asterisk to use? How would faxing work? Can that go through asterisk as well? There are many VOIP providers, but these are hosted providers, if we have our own Asterisk PBX, we no longer need a hosted provider? But we still need some sort of provider for phone numbers and to route calls over internet to normal phone lines?
In the future we would also like to be able to call to our warehouse directly without costs. Would we need another Asterisk server on location or can they just log into the existing server directly?

Any help and insight would be appreciated.

EDIT: our company is located in the Netherlands (Europe)

In general you will need:

  • server to run Asterisk on
  • VoIP-ISDN gateway or ISDN PCI card for connecting legacy PBX line to Asterisk
  • new phones (recommend you use medium range IP phones, don’t use the cheap stuff)
  • VoIP provider (you should find tons of them in NL)

If I were you, I would keep the faxes on the legacy ISDN line. Connecting a fax to Asterisk is not the best choice, since Fax via VoIP is always best effort (if you are not using T.38). Talk to your provider to give you a NT box, that has BRI and analog outputs. And you just plug in your fax and fax server to the NT box analog outputs.
If you are not happy with your fax sever, you can check out Free Fax for Asterisk.

You can connect you warehouse telephones directly to your Asterisk server that is in your central office. I recommend that you use a VPN tunnell between the locations.

Since you are quite new to the VoIP and Asterisk world, I would recommend you do a lot of reading before you start setting up your VoIP server. If you do not have the time, hire a professional to make the setup for you. Doing a good and secure Asterisk setup is not an eazy thing …

Thanks for the pointers. I’ve been reading for a day now and plan to keep reading today too, before i try anything ( wiki,, and these forums of course).

If i want to connect the fax to the asterisk server, i would need an additional analog pci card (or a card with analog and isdn), right? at the moment we are using an old (but trusted!) USR Courier modem hooked up to our linux server with hylafax, which works pretty good. so even if we have to keep using pstn for fax, it wouldn’t be that big a problem.
i was planning on using AsteriskNOW, i downloaded the newest version and from what i read, version 1.8.x should be installable, but does not have the T.38 gateway, but i can install free fax for asterisk. Any downsides to Free Fax for Asterisk versus the T.38 gateway in version 10.x? Apart from only having one channel (but we can always pay for more channels if needed).

are there any converters that will let you use the old analog phones with and asterisk server? these siemens phones weren’t cheap, but i guess even if there are, all the extra buttons wouldn’t be supported.
any recommendation for a hard phone not too expensive with extra buttons to transfer calls between the users of the asterisk pbx? I did come across the Aastra 57i while reading up, which is too expensive, but it’s smaller sibling the 53i is affordable. Are there any cheaper phones like the 53i?

As for an VOIP provider i was looking into and after comparing prices. Radik supports T.38, but each sip trunk only has 1 channel. As for Belcentrale, they have yet to reply to my email about sip trunking and T.38 support.

Thanks for all the help.

I’ve connected a FAX and modem to a Linksys PAP2T before and it has worked fine. I know someone who is using about 8 of these for this very purpose. There are a number of ATA’s (Analogue Telephone Adapters) out there that will work for this application. The connect analogue devices and use SIP to speak to the Asterisk server. If you want an ISDN-PRI card have a look at Sangoma (as well as Digium of course).

Ok, so the PAPT2 would be a good alternative to hook up the FAX to the asterisk box instead of getting a hardware card. If i use an ATA like the PAPT2, can you still transfer calls to other extensions (what if two analogue phones are connected to the PAPT2)?

been reading a lot and have set up a small test server now and testing some stuff out. ordered a Siemens OpenStage 10 ip phone to test with, which was quite cheap (around 50eur shipped), so maybe there is no need to reuse the old analogue phones to save money.

now if only i could get that outbound calling working… back to reading…

thanks for all the info, it’s really helping out. thanks