URN
example: resolver discovery (across), resolver query (down)
URN part1
DNS
server a1
server b1
URLn
web
server n1
page
(redirect)
web
browser
URLb
web
server b1
URLc
.
.
.
.
.
.
DNS
server a2
. . .
DNS
server ai
web
server n2
. . .
web
server nz
web
server b2
. . .
web
server bj
id-a1
id-b1
id-b2
id-a2
id-c1
id-c2
id-b1
id-b2
id-n2
id-n1
.
.
.
.
.
.
Browser discovers resolver
with DNS NAPTR query manager using name authority prefix
found in URN, combines result with URN to form URLb, then
attempts to get page URLb
User
NAPTR
query
manager