[asterisk-biz] Mobile extensions from Asterisk - HLR registration?

Wed May 20 16:18:24 CDT 2009

Hi all,

Interesting thread that I might be able to assist with, for as some will
know I acquired a uk gsm licence and thus the regulatory elements, gsma
membership etc that enabled access to the roaming world with the
necessary ss7 map elements including vlr etc - it will be a couple more
months to complete a meaningful roaming foot print for the US, but I'm
pleased to announce that I've finally got commercial service up in part
of London here in the UK', including signalling connections with the
bigger ss7 world. I have been an enthusiast of asterisk and ss7asterisk
for a while now, so pretty easy to offer SIP interconnect, I've yet to
fully work out how to open up the sms signalling, perhaps some api
development is still needed, however what would be useful is input on
the size of the potential niche and thoughts on what service/s would be
worthwhile bearing in mind the higher voice roaming rates (always higher
with international roaming with domestic roaming much harder to
achieve). Sms is potentially very different with only a very small
number of mno's operating other than a bill and keep model. 

Regards
Magnus 

> -----Original Message-----
> From: asterisk-biz-bounces at lists.digium.com [mailto:asterisk-biz-
> bounces at lists.digium.com] On Behalf Of David Burgess
> Sent: 20 May 2009 18:50
> To: Commercial and Business-Oriented Asterisk Discussion; John Todd
> Subject: Re: [asterisk-biz] Mobile extensions from Asterisk - HLR
> registration?
> 
> John -
> 
> Naturally, if you find such a service, I am eager to know about.
> 
> To address your closing questions, the mechanics of standard GSM
> roaming are something like this:
> 
> * SP-B assigns your MSISDN E.164 when you are provisioned.  All calls
> placed to the MSISDN get routed to SP-B's HLR and then forwarded from
> there to a hidden temporary E.164 called the MSRN, which is assigned
> by a VLR somewhere.  (More on the VLR next.)
> 
> * Where ever you roam, even within SP-B's own network, you never deal
> with the HLR directly.  Instead, you deal with VLRs.  When you
> register with a network, the VLR assigns you an MSRN and reports the
> {MSRN,ISMI} pairing to SP-B's HLR so that inbound calls are routed
> correctly.  Note that all calls are routed as roaming calls through
> VLRs, even when you are within your home network.
> 
> * In the proposed service, when you "roam" to SP-A, SP-A assigns you
> a local MRSN.  SP-A then contacts SP-B's HLR and reports the
> {MSRN,IMSI} pairing.  To do this, SP-A needs to appear to SP-B's HLR
> as a VLR.  From an implementation standpoint, this probably means
> operating a full-featured SIP-GSM/MAP gateway and having peering
> agreements with GSM carriers.
> 
> * As long as SP-A's roaming registration is in effect, all calls
> placed to your MSISDN get forwarded to SP-A's MRSN by SP-B's HLR,
> then, presumably, terminated in whatever device or third-party
> network you have registered with SP-A.
> 
> * The most recent {MSRN,IMSI} registration is effective.  To my
> knowledge there is no mechanism for conflicts.
> 
> [That's a slight simplification, but any real GSM operator is welcome
> to correct any of that if I got it wrong or left our something really
> important for this discussion.  I've punted on the SMS part of the
> question, which includes a whole extra layer of routing among the
> SMSCs, but has a similar theme to it.]
> 
> You only need one GSM carrier to step forward and act as SP-A,
> assuming it doesn't get them black-balled from the GSM Association.
> The ideal candidate would be a company that already operates both
> VoIP routing services and a PLMN-connected GSM VLR.  It could be a
> valuable service.  If I weren't neck deep in a lawsuit with Martone
> Radio Technology, I might be out raising capital to do this myself,
> since we will eventually need a service like this to act as a roaming
> clearinghouse for OpenBTS systems.
> 
> -- David
> 
> 
> On May 20, 2009, at 8:00 AM, John Todd wrote:
> 
> >
> > I've posed this question in person to people with some frequency
over
> > the last few years, and the answer has always been "No, I don't know
> > of such a service." but I'll try on the list and see what I get.
> >
> > I think it would be a great asset to the Asterisk community to have
a
> > service provider (let's call them "SP-A") who is a mobile carrier
who
> > offered the following method: if I register a SIP entity with their
> > servers, they would then register with the HLR of my mobile carrier
> > ("SP-B") and act as if I was roaming into a mobile network operated
> > by  SP-A.  SP-B would then take all calls and text messages destined
> > for my mobile device and send them to SP-A.  SP-A in turn would then
> > relay those calls and messages to my Asterisk server, via SIP and/or
> > XMPP.
> >
> > I would have pre-registered my mobile number with SP-B and
> > authenticated that I was the owner of that mobile number.  SP-A
would
> > hopefully charge very little for the calls - perhaps a slight
premium
> > on what I'd expect for a SIP carrier.
> >
> > This would, I believe, quickly make Asterisk a roaming-capable
> > solution for mobile devices.  Local Asterisk servers would be able
to
> > (as an example) detect dual-mode devices and then route calls in the
> > office in the appropriate manner.  Bluetooth could be used as the
> > "trigger" for non-dual-mode phones.  I have faith that Asterisk
> > developers and administrators would descend upon this type of
service
> > like locusts.  The trick would be to make it purchase-able by
> > individuals, and not as some large-scale process that involved sales
> > contracts and NDAs and the like.  This needs to be a web form, a
> > credit card/paypal account, and some good documentation.
> >
> > Potential problems: what if my mobile phone is registered with SP-A
> or
> > some other provider already?  Who gets the messages?  How do HLRs
> > manage multi-registration conflicts?
> >
> > JT
> >
> >
> > ---
> > John Todd                       email:jtodd at digium.com
> > Digium, Inc. | Asterisk Open Source Community Director
> > 445 Jan Davis Drive NW -  Huntsville AL 35806  -   USA
> > direct: +1-256-428-6083         http://www.digium.com/
> >
> >
> >
> >
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> 
> David A. Burgess
> 
> OpenBTS on the web:
> http://www.kestrelsp.com/OpenBTS
> http://openbts.blogspot.com
> http://www.gnuradio.org/trac/wiki/OpenBTS
> 
> 
> 
> 
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