On 17 Jul 2007, at 11:26, Steve Kennedy wrote: > On Tue, Jul 17, 2007 at 11:56:35AM +0200, Anselm Martin Hoffmeister > wrote: > >> Am Donnerstag, den 12.07.2007, 16:57 -0700 schrieb Russ McBride: >>> Newbie question(s): >>> From what I can determine it sounds like the SMS messaging isn't as >>> robust as it could be (?). I'm wondering if there's active work on >>> that right now or if it's more of an issue about PSTN carrier that >>> one would be using who would be responsible for passing the messages >>> into the PLMN. >>> Background-- I'm looking into the possibility of setting up an >>> emergency messaging system here at the University that would send >>> out >>> voice, SMS, and emails. Any input relevant to that goal would >>> probably be appreciated. >> Hi Russ, >> my personal experience with short messages is that the system >> sometimes >> chews on them for minutes, sometimes several hours, even inside one >> mobile network, from cell phone to cell phone. This surely screws >> using >> it as a primary tier emergency system, but as a backup after e- >> mail and >> automated phone-out that could be OK. Sending from web-interfaces >> or via >> Uwhatever-that-protocol-is-called will not improve the overall >> performance. > > SMS was never designed for guaranteed delivery (or guaranteed timed > delivery). There are options for messages to time out if they're not > delivered in a specified time, or new messages can override old > messages > that haven't been read yet - but delivery isn't guaranteed. > > A phone sending an SMS will try and establish a connection (sort > of) all > the way through to the receiving phone and then deliver the > message, if > it cant it will be sent to the receiving network's SMSC which will > then > try and deliver it. If it gets put into a queue then the delivery time > will vary drastically depending on the load on the SMSC and other > network characteristics. > > Fixed to SMS always goes through an SMSC, so delivery times vary. > > Steve
Just to add, that there is a delivery receipt option you can set on the sending message. If your code watches for this receipt , it can tell when/if an SMS has been delivered to the destination phone. Tim. _______________________________________________ --Bandwidth and Colocation Provided by http://www.api-digital.com-- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
