B.4 DNS procedures 3GPP clarifications for Network Capability

29.3033GPPDomain Name System ProceduresRelease 17Stage 3TS

When the app-protocol as input to the S-NAPTR procedure has the substring with at least +nc included, then any app-protocol returned from DNS shall be considered to match as follows. The characters following the +nc follows the ABNF grammar as follows.

"nc-" (NETCAP)*( "." NETCAP)

NETCAP = 1*5(DIGIT / ALPHA)

DIGIT = %x30-39; 0-9

ALPHA = %x41-5A / %x61-7A; A-Z / a-z

A record with any NETCAP matching the input <network capability> value shall be considered as matching. As an example, x-s5-gtp+nc-nr as S-NAPTR input shall match a record with x-s5-gtp+nc-nr.5gs, but shall not match a record with x-s5-gtp+nc-nrs.

Annex C (Informative):
DNS Pseudo-Code