C.4 Generic DHCP test procedure for IPv4

34.229-13GPPInternet Protocol (IP) multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Part 1: Protocol conformance specificationRelease 16TSUser Equipment (UE) conformance specification

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

The generic test procedure (according to RFC 2131[55]):

1 If the UE already knows a DHCP server address, it goes to step 3. Otherwise, the UE sends a DHCPDISCOVER message locating a server.

2 The SS responds with a DHCPOFFER message.

3 The UE sends a DHCPINFORM message requesting P-CSCF address(es) in the options field.

4 The SS responds with a DHCPACK message providing the IP address of the SS as P-CSCF address.

Expected sequence

Step	Direction		Message	Comment
	UE	SS
1	🡪		DHCPDISCOVER	Optionally sent if UE does not have DHCP server address.
2	🡨		DHCPOFFER	Sent if DHCP Discover message is received.
3	🡪		DHCPINFORM	Requesting P-CSCF Address(es).
4	🡨		DHCPACK	Including P-CSCF IP Address.

NOTE: The default message contents in annex B are used.