Assigning VoiP service to analogue fax

Posted on 2011-10-12
Last Modified: 2012-05-12
Hi All,

In need of some advise, we currently have sevice VoIP numbers which we purchase via a reputable SIP provider, at our current location we do not have any PSTN lines so I am wanting to know how I would go about assigning one of these VoIP numbers to an analogue fax machine to send and receive faxes from (using the VoIP number).

I have tried playing around with a Cisco spa3102 which I thought may have supported the facilitation of assigning the VoIP number to the (spa3102) box and then converting this back to a traditional analogue or PSTN service, but unfortunately from what I can tell it appears as though the functionality is to support this is not present within the spa3102 device.

If anyone has any advise on how to best facilitate the above to successfully have our fax service using a VoIP number that would be greatly appreciated as I am desprately trying to get this to work.

Thanks in advance,
Question by:Adma1
    LVL 15

    Expert Comment

    Can you give us a better idea of what your "SIP" provider is handing you? More than likely the issue is going to be on their end in terms of them not allowing the function or you just aren't paying for that functionality from them. FWIW: the spa3102 does support this function both in terms of fax.
    G.711 pass-through or real-time fax over IP via T.38

    Hope this helps.
    LVL 11

    Expert Comment

    The 3102 supports the fax on the FXS port. You would need to program the device with the user name and password of one of you VoIP numbers. If your provider sends you all of you numbers with a single login, you may have to register the device with them and let them route the number to your device. If your provider has individual accounts for each number just use one of these to program the device. The former is much more likely though so you may be better off calling your provider.
    LVL 36

    Expert Comment

    T.38 would be your only reliable option. Fax over G711 is ok over a local lan but over the internet can be unreliable. Some fax machines will be more badly affected than others.

    Author Comment

    Ok thanks everyone for the advise, would anyone have any documentation which could assist with connfiguring the spa3102?

    Thanks again
    LVL 11

    Accepted Solution

    Here is a link to the manuals and some guides for configuring it.
    Cisco SPA3102 Info

    Here is a guide to configuring the 3102 to a VoIP provider.
    Configure a Linksys SPA-3102 ATA to a VoIP Provider

    Here is a link to a configuration Wizard that cen help you configure it for your provider.
    Configuration Wizard

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