Vijay, Yes, I know we are talking SDP, but the SDP ABNF was so imprecise that I looked elsewhere. I am not sure where the definitive source is, but I just took SIP as an example, which seemed to suggest that the people who wrote RFC 3261 thought that a single element (without any dot) was wrong. This could mean that if you take a single element and use it as input to the DNS mechanism, you get the wrong outcome, and hence including a single element in SDP would be equally wrong. Kevin's message seems to support that belief. John > -----Original Message----- > From: Vijay K. Gurbani [mailto:vkg@xxxxxxxxxxxxxxxxxx] > Sent: 05 February 2010 16:32 > To: Elwell, John > Cc: sipping@xxxxxxxx > Subject: Re: [Sipping] Question on draft-ietf-sipping-v6-transition-07 > > Elwell, John wrote: > > Thanks, but I was concerned that a domain name beginning with "." > > might be wrong; Taking the SIP ABNF as an example (SDP ABNF isn't so > > precise), we have: > > > > hostname = *( domainlabel "." ) toplabel [ "." ] > > John: Quite true. However, in the case we are talking about, > the ".invalid" appears in the SDP, which is governed by the > SDP ABNF. The ".invalid" is not appearing in the URI, but > in the "c=" line in SDP. > > The SDP ABNF in rfc4566 has this grammar for the > "c=" line: > > connection-field = [%x63 "=" nettype SP addrtype SP > connection-address CRLF] > connection-address = multicast-address / unicast-address > unicast-address = IP4-address / IP6-address / FQDN / extn-addr > extn-addr = non-ws-string > non-ws-string = 1*(VCHAR/%x80-FF) > ;string of visible characters > > Does not ".invalid" in the SDP result from the extn-addr > production rule above? Consequently, should it not be legal? > Or am I missing something here? > > Thanks, > > - vijay > -- > Vijay K. Gurbani, Bell Laboratories, Alcatel-Lucent > 1960 Lucent Lane, Rm. 9C-533, Naperville, Illinois 60566 (USA) > Email: vkg@{alcatel-lucent.com,bell-labs.com,acm.org} > Web: http://ect.bell-labs.com/who/vkg/ > _______________________________________________ Sipping mailing list https://www.ietf.org/mailman/listinfo/sipping This list is for NEW development of the application of SIP Use sip-implementors@xxxxxxxxxxxxxxx for questions on current sip Use sip@xxxxxxxx for new developments of core SIP
