Example (strict router 가 있는 경우)

Scenario : U1 -> P1 -> P2 -> P3 -> P4 -> U2 (P3 : strict router)
U2에 도착한 INVITE
Contact: sip:caller@u1.example.com
Record-Route:
Record-Route: 여기 lr 이 없다.
Record-Route:
Record-Route:


BYE Message (U2->P4)
BYE sip:caller@u1.example.com SIP/2.0
Route:
Route:
Route:
Route:


P4 -> P3 (P3 strict router)
BYE sip:p3.middle.com SIP/2.0
Route:
Route:
Route:


Scenario : U1 -> P1 -> P2 -> P3 -> P4 -> U2 (P3 : strict router)
P3 -> P2
BYE sip:p2.example.com;lr SIP/2.0
Route:
Route:
P2 -> P1
BYE sip:caller@u1.example.com SIP/2.0
Route:
P1 ->U1
BYE sip:caller@u1.example.com SIP/2.0