> I think there is one benefit > *when the caller dialed a wrong number!* > > If overlap signallig were used, the caller might be > informed by the proxy immediately. In en bloc > signalling, however, the caller will only be altered > after he dialed the complete wrong number > watsting time and resources.
I'm not sure you who's time and resources that you are indicating that it wasted: the user's or the network's. The continuous INVITE/484/ACK exchanges as the user enters digits waste network resources. And because SIP hasn't resolved the HERFP issue, the continuous INVITE/484/ACK exchanges may involve different servers. Thus it can uselessly waste even more resources. Similarly the outbound device potentially might not behave as expected. For instance, it might return a 18x and connect the device to media treatment instead of immediately returning 484. ------------------ Original ------------------ From: "Brett Tate"<[email protected]>; Date: Tue, Jul 16, 2013 01:19 AM To: "SIP Learner"<[email protected]>; "sip-implementors"<[email protected]>; Subject: RE: [Sip-implementors] Overlap signaling in a native SIP network > In PSTN networks, it's beneficial to try to establish > a connection between the caller and the callee before > the full phone number digits are collected. But SIP > works over the connectionless IP network, is there any > benefit to use overlap signalling in a native SIP network? I'm not aware of any benefit; however RFC 3261 defined 484 to allow for it. RFC 3398 and RFC 3578 discuss the ISUP conversion. . _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
