TCP/IP Tutorial and Technical Overview - IBM Redbooks

The mobility agent responds to a registration request with a registration reply and
with a destination port copied from the source port of the registration request.
Figure 7-5 shows the registration reply format.
Figure 7-5 Mobile IP: Registration reply
Where:
Type 3.
Code Indicates the result of the registration request:
0 Registration accepted.
1 Registration accepted, but simultaneous
bindings unsupported.
64-88 Registration denied by foreign agent.
128-136 Registration denied by home agent.
Lifetime The number of seconds remaining before the registration
is considered expired. (Code field must be 0 or 1.)
Home address Home IP address of the mobile node.
Home agent IP address of the mobile node's home agent.
Identification A 64-bit identification number used for matching
registration requests with replies.
Extensions A number of extensions are defined, all relating to
authentication of the registration process.
For full details of these messages, refer to RFC 3344.
Chapter 7. Mobile IP 283