Hi Hans, Since an ST address signal is always added to the last digit of the called party number (Is this really the case, at least in the ITU version?), I guess ST is used by the last SAM to indicate that it is the last one. As I failed to find any standard that documents this behavior clearly, I doubt whether it is the right answer and I hope some guy will kindly help me out with this issue! Thanks! -------------------------------------------------- From: "Johann Steinwendtner" <steinwendtner@xxxxxxx> Sent: Monday, October 12, 2009 2:30 PM To: <asterisk-ss7 at lists.digium.com> Subject: Re: A question about ISUP SAM message usage > Tian schrieb: >> As you know, when overlap signaling is used, when enough digits have >> been collected to identify the next exchange, an IAM is sent to the next >> exchange along the route to the called party, the remaining digits are >> sent in subsequent SAM messages. >> >> My question is: how does the local exchange of the called party decide >> whether all digits of the called party number has been collected or not >> (i.e., how does the local exchange of the called party know whether or >> not the SAM it received is the last one), especially when the called >> party number is of variable length? > > I depends on the type of called party I guess. If the called party > supports > a message like "end of digit collection" than this would be translated > into an ACM message. e.g. if the called party is an ISDN interface > terminating to a PBX, the pbx would send a call proceeding or an alert > which will then be translated to an ACM. > If there is no "end of digit collection", than an End of dial (EOD) timer > will be used. > It depends totally on the type of gateway. > > Best regards > > Hans > > > _______________________________________________ > --Bandwidth and Colocation Provided by http://www.api-digital.com-- > > asterisk-ss7 mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-ss7 >
|