GSM gateways in the US?!?
$subj says it pretty much all :) Does anybody use anything like this in the US? The $1 mil/yr costs of our cellular telephony consists, almost exclusively, of calls made from cell phones, back into the company's various sites PBXs. I have seen such things advertised in Europe, with the extraordinary benefit of (by using a GSM gateway) making all calls appear "inside the GSM network", thus very low cost, or, sometimes, even free ... TIA, Stef
$subj says it pretty much all :) Does anybody use anything like this in the US?
I doubt it. Europe is all calling party pays, so if you can sneak your calls into the cell network and avoid the termination fees, you can save vast amounts of money. North America is all mobile party pays, so calls to mobile cost the same as calls to landline. Indeed, with LNP it's impossible to tell which numbers are mobile and which are landline unless you have access to the LNP databases. R's, John
On Jul 24, 2005, at 3:35 PM, John Levine wrote:
<snip>
North America is all mobile party pays, so calls to mobile cost the same as calls to landline. <snip>
... not inside the [same provider's] mobile network, cell phone to cell phone. See T-Mobile's "Unlimited Mobile-to-Mobile" component of their services, as an example. This (unlimited, for a flat, usually minuscule, fee) is what I am hoping to achieve with a gateway (making the PBX behind it look like any other mobile phone). Stef
North America is all mobile party pays, so calls to mobile cost the same as calls to landline.
... not inside the [same provider's] mobile network, cell phone to cell phone. See T-Mobile's "Unlimited Mobile-to-Mobile" component of their services, as an example. This (unlimited, for a flat, usually minuscule, fee) is what I am hoping to achieve with a gateway (making the PBX behind it look like any other mobile phone).
I don't understand where you're planning to save money here. Calls into a mobile network are free for the caller under any circumstances. The free mobile-to-mobile deals apply only to the mobile phone user; if I have it, calls to or from my mobile from other users on the same network are free to me, but the other party still pays whatever his plan says. If your calls aren't placed from a mobile they're free anyway (or whatever your landline rate is, which should be pretty close to free) so where's the savings? If, nonetheless, you want to experiment with this kind of hack, look for devices with names like cellsocket and dock-n-talk that take a cell phone and provide a landline interface that you should be able to connect to a PBX. R's, John
On Sun, 24 Jul 2005, John Levine wrote:
... not inside the [same provider's] mobile network, cell phone to cell phone. See T-Mobile's "Unlimited Mobile-to-Mobile" component of their services, as an example. This (unlimited, for a flat, usually minuscule, fee) is what I am hoping to achieve with a gateway (making the PBX behind it look like any other mobile phone).
I don't understand where you're planning to save money here. Calls into a mobile network are free for the caller under any circumstances.
I've recently been thinking about the same thing, so I think I get it. Suppose you have a staff of people with CarrierX cell phones, and CX offers free calling within their network. So all your staff can call each other's CX cell phones from their own CX cell phones at no cost above the regular flat monthly fee. Now, suppose your office regularly needs to call those cell phones. Sure, calling from your LEC lines doesn't cost you anything, but it burns up the callee's limited cell<->pstn minutes. If you could somehow interface your PBX to the CX network and place calls into the CX network without burning up callee minutes, that could potentially save you considerable money. Assuming CX won't allow you to actually interconnect with them in the "normal" way phone networks interconnect, you could perhaps do so by interfacing CX cell phones (or something that would look like them to CX) to your PBX.
If, nonetheless, you want to experiment with this kind of hack, look for devices with names like cellsocket and dock-n-talk that take a cell phone and provide a landline interface that you should be able to connect to a PBX.
Cellsocket sounds familiar...I think I have a friend using one of those to provide a phone line to his personal asterisk server. ---------------------------------------------------------------------- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net | _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________
On Sun, 24 Jul 2005, Jon Lewis wrote:
On Sun, 24 Jul 2005, John Levine wrote:
... not inside the [same provider's] mobile network, cell phone to cell phone. See T-Mobile's "Unlimited Mobile-to-Mobile" component of their services, as an example. This (unlimited, for a flat, usually minuscule, fee) is what I am hoping to achieve with a gateway (making the PBX behind it look like any other mobile phone).
I don't understand where you're planning to save money here. Calls into a mobile network are free for the caller under any circumstances.
I've recently been thinking about the same thing, so I think I get it.
Suppose you have a staff of people with CarrierX cell phones, and CX offers free calling within their network. So all your staff can call each other's CX cell phones from their own CX cell phones at no cost above the regular flat monthly fee. Now, suppose your office regularly needs to call those cell phones. Sure, calling from your LEC lines doesn't cost you anything, but it burns up the callee's limited cell<->pstn minutes. If you could somehow interface your PBX to the CX network and place calls into the CX network without burning up callee minutes, that could potentially save you considerable money. Assuming CX won't allow you to actually interconnect with them in the "normal" way phone networks interconnect, you could perhaps do so by interfacing CX cell phones (or something that would look like them to CX) to your PBX.
If, nonetheless, you want to experiment with this kind of hack, look for devices with names like cellsocket and dock-n-talk that take a cell phone and provide a landline interface that you should be able to connect to a PBX.
Cellsocket sounds familiar...I think I have a friend using one of those to provide a phone line to his personal asterisk server.
---------------------------------------------------------------------- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net | _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________
I've heard rumors that some cell providers have a solution for corperate campus enviroments... essentially where there is a private cell site or something along those lines. I think cingular has a product along those lines. Can anybody confirm? I've only heard this as we drecently re-did our phone system and the sales people were trying to sell us on everything under the sun. -Justin Kreger On Sun, 24 Jul 2005, Jon Lewis wrote:
On Sun, 24 Jul 2005, John Levine wrote:
... not inside the [same provider's] mobile network, cell phone to cell phone. See T-Mobile's "Unlimited Mobile-to-Mobile" component of their services, as an example. This (unlimited, for a flat, usually minuscule, fee) is what I am hoping to achieve with a gateway (making the PBX behind it look like any other mobile phone).
I don't understand where you're planning to save money here. Calls into a mobile network are free for the caller under any circumstances.
I've recently been thinking about the same thing, so I think I get it.
Suppose you have a staff of people with CarrierX cell phones, and CX offers free calling within their network. So all your staff can call each other's CX cell phones from their own CX cell phones at no cost above the regular flat monthly fee. Now, suppose your office regularly needs to call those cell phones. Sure, calling from your LEC lines doesn't cost you anything, but it burns up the callee's limited cell<->pstn minutes. If you could somehow interface your PBX to the CX network and place calls into the CX network without burning up callee minutes, that could potentially save you considerable money. Assuming CX won't allow you to actually interconnect with them in the "normal" way phone networks interconnect, you could perhaps do so by interfacing CX cell phones (or something that would look like them to CX) to your PBX.
If, nonetheless, you want to experiment with this kind of hack, look for devices with names like cellsocket and dock-n-talk that take a cell phone and provide a landline interface that you should be able to connect to a PBX.
Cellsocket sounds familiar...I think I have a friend using one of those to provide a phone line to his personal asterisk server.
---------------------------------------------------------------------- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net | _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________
On 24 Jul 2005, at 19:21, John Levine wrote:
North America is all mobile party pays, so calls to mobile cost the same as calls to landline.
... not inside the [same provider's] mobile network, cell phone to cell phone. See T-Mobile's "Unlimited Mobile-to-Mobile" component of their services, as an example. This (unlimited, for a flat, usually minuscule, fee) is what I am hoping to achieve with a gateway (making the PBX behind it look like any other mobile phone).
I don't understand where you're planning to save money here. Calls into a mobile network are free for the caller under any circumstances.
The original message talked about calls from the mobile network into the office, not calls from the office into the mobile network. Joe
Here is once such vendor of cellular-PSTN gateways, http://www.mobilecomms-technology.com/contractors/gsm/eurotech1/
I've seen cellular service agreements that discuss "all more almost all usage originating from a single cell site". Apparently, they discourage using fixed-location cell adapters to jack-in to the cellular network. I suppose one could use directional antennas on the roof, and target two or more of the cellular provider's cell cites, alternating calls amongst the sites. You couldn't just use PBX routing though. You'd have to distribute the calls from each fixed-location adapter across multiple cell-sites, so an antenna switcher would be needed. (If you're real close to a cell site, you probably can't get an antenna sufficiently directional to ensure that you use a distant tower...) Seems like a lot of work. If you have enough mobiles to make this worthwhile, I'm surprised that the carrier won't cut you a deal to encourage you to stay with them (rather than shopping other carriers for better deal/discounts). If your account really matters, maybe they'll let you set up some VoIP trunking into their MTSO. That would be low cost. At 08:56 PM 7/24/2005, Roy wrote:
Here is once such vendor of cellular-PSTN gateways,
http://www.mobilecomms-technology.com/contractors/gsm/eurotech1/
At 10:43 PM -0400 on 7/24/05, Robert M. Enger wrote:
I've seen cellular service agreements that discuss "all more almost all usage originating from a single cell site". Apparently, they discourage using fixed-location cell adapters to jack-in to the cellular network.
I suppose one could use directional antennas on the roof, and target two or more of the cellular provider's cell cites, alternating calls amongst the sites. You couldn't just use PBX routing though. You'd have to distribute the calls from each fixed-location adapter across multiple cell-sites, so an antenna switcher would be needed. (If you're real close to a cell site, you probably can't get an antenna sufficiently directional to ensure that you use a distant tower...)
Seems like a lot of work. If you have enough mobiles to make this worthwhile, I'm surprised that the carrier won't cut you a deal to encourage you to stay with them (rather than shopping other carriers for better deal/discounts). If your account really matters, maybe they'll let you set up some VoIP trunking into their MTSO. That would be low cost.
At 08:56 PM 7/24/2005, Roy wrote:
Here is once such vendor of cellular-PSTN gateways,
http://www.mobilecomms-technology.com/contractors/gsm/eurotech1/
(this is somewhat off-topic, but does relate to North American Networks in a vague sense...) There are two methods that are obvious to terminate calls into mobile (GSM) networks in North America: Outbound (enterprise-to-mobile): 1) Purchase a PRI-to-GSM channel bank adapter (use Google search terms "pri gsm" for more details) and link it into your PBX, or Asterisk server, or what-have you. Then, buy 23 GSM SIM cards from Carrier C, who offers "free" mobile-to-mobile termination. Then, buy cell phones for all your employees on Carrier C. Put specific routes into your PBX/Asterisk/ENUM routing engine so that anyone dialing any employee's cell number gets routed to the next available channel on the PRI gateway instead of going out to the PSTN. The calls lose meaningful caller ID (it shows up as the number on the GSM chip in that semi-random channel) but administrators gain some ease-of-use at a low introductory price. As you mention, it may be against the policy of the carrier to route calls in this way. This is a popular method to do international VoIP-to-mobile termination in many smaller nations with restrictive telephony laws. Ethernet cables are often seen running out of windows in office parks to a parked van with lots of antennas. The van stays for a day or so, before it shows up on the "abnormal usage" alarm list for the closest cell tower, and then vanishes off to the next IP teat. or 2) Buy all your employees cell phones on Carrier C. Then, contact Carrier C and negotiate a direct PRI into their mobile network, hopefully at a very low rate per month. Put specific routes into your PBX/Asterisk/ENUM routing engine so that anyone dialing any employee's cell number gets routed to the next available channel on the PRI that goes to Carrier C's network. You'd better be doing a boatload of mobile calls, otherwise this is very cost-ineffective due to just the local loop costs, not to mention any service charges. I have spoken to at least two companies who have done this with various carriers (not necessarily GSM) but they were Fortune 100 firms which may give them the clout to make this happen, while smaller companies may just be out of luck. Inbound (mobile-to-enterprise): 1) (using method 1 above) It is unlikely that your employees will be able to efficiently use this method to call INTO the office, since it is unreasonable to ask everyone to remember all 23 numbers on the GSM channel bank. Recall that if a line is busy, there is no "hunt" feature. (I could be proven wrong with this, since I know there is a GSM "forward-on-busy" configuration option, but I have NEVER seen it work correctly on any of the three GSM networks I've tried in the United States, and it's an ugly, ugly hack.) or 2) (using method 2 above) You would need to negotiate with Carrier C to install specific routes for your office trunk prefixes such that any calls originating inside of Carrier C's network would get pumped over the PRI instead of being delivered via LD or ILEC handoff. I don't know if this is possible, but it does make one yearn for a dynamic and filterable way to "announce" e.164 information to carriers (and on this segue, go to the voip-peering list to hear more tales of woe and sorrow about the lack of scale-able inter-carrier or inter-enterprise dynamic routing protocols.) Both methods (1 and 2) require that the administrator know every mobile number that has been allocated to employees, for either outbound routing or outbound announcement. Ideally, it would be great to be able to hand off these calls into and out of mobile carrier's networks via native IP (SIP, most likely) since it saves everyone money and possibly increases security of transport by having fewer entities "touch" the media stream. However, that seems unlikely due to FUD and politics at this time. Anyone knowing of a mobile carrier who will accept enterprise traffic to their voice network via SIP over private or public SIP interconnection should let me know... I've not encountered such enlightenment yet. JT
There are two methods that are obvious to terminate calls into mobile (GSM) networks in North America:
From my cell phone, I can just dial internal extensions (e.g. I can dial 0137720 on my cell phone, and my desk phone rings). This would appear to be
Just to give you a .uk experience, I don't know the technical details of how this is implemented, but from a user's point of view: Outbound (enterprise-to-mobile): My desk phone extension is 01-37720. If someone on the corporate PBX calls 071-37720, that's routed to my cell phone. Full internal CLID works (so my cell phone shows the extension of the caller, rather than an external number) Inbound (mobile-to-enterprise): the most ugly hack on the part of the mobile carrier, as it matches on number length to determine if it's an "internal" or an "external" call. However, it does mean that my cell phone appears to be part of the corporate PBX. According to our Intranet, this gives 30% call savings. Hope this helps, Simon
On 25.07 07:59, Simon Lockhart wrote:
There are two methods that are obvious to terminate calls into mobile (GSM) networks in North America:
Just to give you a .uk experience, I don't know the technical details of how this is implemented ....
These are pretty common plans over here even for enterprises smaller than the BBC. A friend in a medium sized taxpayer funded organisation recently related the following: that organisation had just invested considerably into their PABX, particularly into toll authorisation and billing. Shortly after this was introduced they realised that the national toll volume sharply decreased. They were just about to declare a serious victory for effective cost control when they realised that this was due a change in the corporate GSM plan that allowed essentially free national calling and people in the organisation were making the right choice ;-) This suggests a much simpler solution to this whole problem: Give all the people in the office cell phones for intra-organisational calling. Lacks some call management features, and certainly lacks geek satisfaction, but costs very little to implement....... Daniel
participants (11)
-
Daniel Karrenberg -
jkreger＠earthling.lwolenczak.net -
jkreger＠lwolenczak.net -
Joe Abley -
John Levine -
John Todd -
Jon Lewis -
Network Fortius -
Robert M. Enger -
Roy -
Simon Lockhart