Hello All, Good Day!
We have a query regarding CLIR feature and the use of "user=phone" parameter. According to ITU-T Q.1912.5 and ETSI TS 129 163, for ISUP -> SIP calls, if CLIR is applicable, then "anonym...@anonymous.invalid" shall be sent in 'From' header. There is no mention of use of the "user=phone". Question: Is it incorrect to send "anonym...@anonymous.invalid; user=phone" in this case? Extract from RFC 3261: "The set of valid telephone-subscriber strings is a subset of valid user strings. The user URI parameter exists to distinguish telephone numbers from user names that happen to look like telephone numbers. If the user string contains a telephone number formatted as a telephone-subscriber, the user parameter value "phone" SHOULD be present. Even without this parameter, recipients of SIP and SIPS URIs MAY interpret the pre-@ part as a telephone number if local restrictions on the name space for user name allow it." The argument to not include "user=phone" parameter is: When a tel URL (RFC 2806 [8]) is converted to a SIP or SIPS URI, the entire telephone-subscriber portion of the tel URL, including any parameters, is placed into the userinfo part of the SIP or SIPS URI. Thus, tel:+358-555-1234567;postd=pp22 becomes sip:+358-555-1234567;postd=p...@foo.com;user=phone or sips:+358-555-1234567;postd=p...@foo.com;user=phone So if we try to convert sip:anonym...@anonymous.invalid;user=phone back to tel URL,we can get the following result: tel:Anonymous There is the definition of tel URL in RFC2806: The "tel" URI has the following syntax: telephone-uri = "tel:" telephone-subscriber telephone-subscriber = global-number / local-number global-number = global-number-digits *par local-number = local-number-digits *par context *par global-number-digits = "+" *phonedigit DIGIT *phonedigit local-number-digits = *phonedigit-hex (HEXDIG / "*" / "#")*phonedigit-hex phonedigit = DIGIT / [ visual-separator ] phonedigit-hex = HEXDIG / "*" / "#" / [ visual-separator ] tel:Anonymous is not valid tel URL because Anonymous is not digit. So Anonymous<sip:anonym...@anonymous.invalid;user=phone is invalid. The argument to include the "user=phone" parameter is: Even if CLIR is applicable, if "user=phone" parameter is not included, the info that the calling user was a telephonic user is lost. At the terminating/transit network, the service logic may depend on whether the calling user is a telephonic user or not. Regards, Swami & Sony. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
