Calling home, free of charge

I’ve just been through a period of travel hell; individually each of the the three back-to-back trips are interesting, useful, and in some ways, quite good fun. But they’re back to back. So over a 17 day period, I’ve actually had only 3 days in the UK, and two of those I was still working. Of course, mention business travel to anyone that doesn’t do it, and it brings to mind visions of exotic locations and lavish expense accounts. Whereas the reality tends to be cramped economy class travel, very long working days, and lonely hotel rooms a long way from friends and family.

More importantly it means that just doing the normal day to day family things, like chatting to your kids about their day in school can rapidly become an extortionately expensive luxury that you feel ought to be kept to the brief minimum. Especially when the company that you’re travelling for thinks that it shouldn’t pay for those phone calls – which particularly irks me.

And that got me thinking – I actually have all the facilities I need to enable me to call home to my family for nothing. My company expects me to need an Internet connection in whatever hotel I stay in, and fully funds it. I carry a laptop and an Android Smartphone. In combination with the rather sophisticated phone that I have at home, I can talk to my family for as long as I want for no additional costs, using a technology called VoIP, based on an open standard called SIP.

My home phone is a Siemens Gigaset S685 IP DECT system, with 5 handsets. It’s what the marketing world likes to term “pro-sumer”, by which they really mean it’s got lots of features that most consumers will never use, but it’s not really got enough features for true commercial use. They also mean it’s a bit expensive for a consumer product.

But in this case, we’re talking about a DECT phone that connects to both my home phone line and my home broadband, and can have up to 7 logical phone lines connected to it – the physical “POTS” line, and 6 VoIP connections over the internet. The base unit can support separate conversations on up to 3 lines in parallel, with as many handsets connected to each of those lines as required. Each handset can act as a speaker-phone, or have either a headset or bluetooth earpiece attached to. It can even do call routing, where it looks at the number you dial, and decides which line to place your call on. In short, it’s absolutely packed with features.

The key to the free calls home is of course, the VoIP lines, because as of version 2.3, Android can also make VoIP calls. The trick is simply getting the two to talk to one another, while they are in different countries.

So first you need to find a SIP provider for your home phone and your Smartphone. The best way that I’ve found to do this is to set up a SIP-based virtual PBX. You create a free account with them (your PBX) and then add users to your PBX. Each user is given their own SIP credentials so they can logon, and you can associate an extension number with each of those users, allowing them to easily exchange calls – which is exactly what I need, as (unlike my Android smartphone) the handsets on my old Gigaset cannot call SIP URI’s directly.

The first provider I came across that allows this is OnSip, in the USA. My experience with them has been good, but there are many others out there too. Unfortunately it’s not perfect – for me, there are a couple of quirks with their service. Firstly, they don’t seem to expect anyone outside the USA to be using their service, so I cannot enter my address correctly. Which I suspect is technically a breach of their T&C’s. And secondly, it means that all the call tones you’ll hear when using this (ringing, engaged, unobtainable etc) will be American rather than British. I can live with that, but if you choose to go down this route too, DO NOT ENABLE THE E911 OPTION. You could theoretically call out US emergency services to whatever pseudo-fictitious address you have registered with them, which would not be good.

To make it work:

  1. Register with your chosen free SIP PBX provider. I’ll assume OnSip, who will ask you to register a userid, then validate it by email, before letting you set up your first PBX.
  2. Registering for OnSip PBX

    Registering for OnSip PBX

    When you come to define that PBX, you’ll see a screen similar to this one, asking for initial configuration information. You can call the domain name (which is essentially the Internet name of the PBX) anything you like. Incidentally, changing that country field seems to do nothing. It doesn’t even change the format of the information they collect for your address or (real) phone number.
  3. Creating a new user

    Creating a new user

    Having now got a SIP PBX available, we can add some users to it. Each user is roughly equivalent to a telephone on a normal PBX, but in this case the user accesses the PBX by way of some SIP credentials. The users can be called via those credentials, or (if the caller is another user of this PBX) the extension number that is associated with that user. This happens irrespective of the device that the user is using those credentials on, or its location.
  4. List of virtual PBX users

    List of virtual PBX users

    After entering a user for the Gigaset (my house phone) and one for my smartphone, I have a PBX with two users associated with it. I’ve obscured some critical pieces of information to maintain some privacy, but fundamentally the OnSip system gives me a set of SIP credentials for each “user” of the system (bottom right on the image), and associates an extension with them too.
  5. Next we need to get the Gigaset to register with the SIP PBX. To do this, logon to the Gigaset web interface, select the “Settings” tab, and then navigate to Telephony, Connections.
    Gigaset VoIP providers


    Gigaset Basic VoIP Provider Settings
    Gigaset Advanced VoIP Provider Settings Gigaset Settings

    Now define a new provider by clicking on one of the “Edit” buttons as seen in the first of these screenshots. This will bring up the basic settings page seen in the second screenshot. Into this screen enter the data found on the OnSip user configuration screen under the Phone Configuration heading. Copy the OnSip username field into the Gigaset username field, the OnSip Auth Username field into the Gigaset Authentication Username field, the OnSip SIP Password into the Gigaset Authentication Password field, and then click the “Show Advanced Settings” button, which will extend the form with the additional fields seen in the third screenshot. Now copy the OnSip Proxy/Domain field into the four Gigaset fields: Domain, Proxy Server Address, Registrar Server, and Outbound Proxy. When you save the settings the Gigaset will attempt to register with the OnSip PBX. Sometimes this takes a few seconds. You may need to refresh the browser to see the status change to Registered.
  6. Now we need to make the Android Smartphone register to the OnSip PBX too. To do this, bring up the Android Settings by pressing “Menu” from the home screen, and tap “Settings”.
    Android Call Settings


    Android Internet Calling (SIP) Accounts
    Android SIP Account Details Android SIP setup

    Navigate to the Call Settings, and tap it to reveal the screen in the first screenshot.
    Tap on “Use Internet Calling” and set it to “Ask for each call”. Then tap on Accounts to bring up the Internet Calling (SIP) Accounts screen where we can enter SIP accounts associated with the phone. See the second screenshot.
    Now add a new account for the OnSip PBX by tapping “New Account”; this will bring up a screen like the one shown in the third screenshot, into which you need to enter your credentials.
    The content of each of the fields (from the OnSip phone configuration information) should be obvious by now. When you save the account you will want to check that the registration information is correct. The easiest way to do this is to enable the “Receive incoming calls” option (back on the first screenshot again), which will force Android to register all it’s accounts with their associated providers. If you get an error then either the provider is down (possible) or the settings are incorrect (more likely). Leaving this option enabled forces Android to keep those connections active, which runs all the radios, and eats the battery, but allows incoming VoIP calls to your Smartphone (say from the Gigaset). In my experience it’s too power-hungry to use in this mode, other than very sparingly. Fortunately you can make outgoing calls from the Smartphone without enabling it.
  7. Android Internet Calling enabled Contact

    Android Internet Calling enabled Contact

    Finally you need to define a contact in the Smartphone contacts to use with Internet Calling. As all my contacts are normally managed by Lotus Traveler for me, which has no concept of Internet Calling, I defined a new local-only contact that is not synched with any of my Accounts (ie, Google or Lotus Traveler) and used that. Enter the name of the contact as normal, then scroll all the way to the bottom of the contact, where you will find a “More” section. Expand that, and continue to scroll to the bottom, where you will find a field for “Internet call”; into that simply enter either the OnSip SIP URI of your Gigaset, or it’s OnSip extension number.

Note that this really only works when connected to a reasonably good quality WiFi network. Poor quality networks seem to give quite variable results. Sometimes they still work, other times one end or the other may experience audio problems and/or dropped calls. It seems to work just fine through both the IBM and my home firewalls, even at the same time. I’ve not checked the actual audio codecs in use, but sound quality is subjectively better than a normal cellular call. Neither Android or the Gigaset seem to do silemce suppression (ie injection of white-noise when no-one is speaking) so the pauses in a conversation are totally silent, which can be slightly disconcerting.

Normally if you want to dial the Smartphone from the Gigaset you would need to indicate to the phone that it should send the call over the appropriate VoIP provider. This quickly becomes a pain, but it’s easy to set up a simple dial plan on the Gigaset so calls that start “700” (remember I made my extensions be 7000 and 7001?) go out over the OnSip VoIP connection automatically, which makes the solution really easy to use (ie family-friendly) from the Gigaset.

Finally, there is a really interesting technology called iNum available. Sadly it’s not (as far as I can tell) implemented by any of the major telecoms ISPs in the UK, that when combined with SRV records in special DNS records, would allow some really cool automatic rerouting of calls over different networks to different endpoints, depending on context. In theory the network could understand whether I was at home or out with my mobile, and route the call appropriately. It could also do smart things like look at the inbound number and the time, and route business calls to voicemail out of office hours, but still let personal calls through as normal.

If only it were implemented.

Advertisements

3 thoughts on “Calling home, free of charge

  1. Thanks, Richard. That’s been really useful, having suffered at the hands of foreign hotel phone charges too (though slightly less draconian company policy, or possibly just less strictly enforced). I’ve now got our Android phones and home Gigaset phones hooked up successfully with little effort, and frankly I’d never have figured it out without your guide!

    We really must try and get together soon 🙂

    Andy.

  2. Richard, thanks for riding point. Stumbled into the long grass only when setting up a 3CX Softphone. Not too many places tell you that outbound proxy server needs to be set to: sip.onsip.com 😉

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s