Subject: Re: [MOBILE-IP] A question on Mobile IP Regional Registration

From: Annika Jonsson <[email-masked]>
Date: Mon, 4 Sep 2000 11:05:31 +0200

At 09:10 2000-09-04 +0300, Dionisios Gatzounas wrote:
>Hi.
>
>I have a question on Mobile IP Regional Registration. This is as follows:
>
>In the <draft-ietf-mobileip-reg-tunnel-03.txt>, when a mobile node determines
>that it is located in a visited domain it performs a home registration.
Suppose
>that the mobile node has acquired a co-located care-of address in the
>visited domain (e.g., with DHCP) but it wishes to use the address of the
GFA of
>the visited domain as its care-of address. The mobile node will then issue a
>Registration Request message with the GFA address in the care-of address
field
>and it will add a Hierarchical Foreign Agent extension including its
co-located
>care-of address.

Correct.

>Does the same applies when the mobile node performs a Regional Registration?
>

Yes.

>To my understanding, when the mobile node performs a handoff from one subnet
>to another within the same visited domain, it issues a Regional Registration
>Request addressed to the GFA. The mobile node includes the GFA address in the
>HA field, the address of the foreign agent of the new subnet in the care-of
>address field (?) and it also adds a Hierarchical Foreign Agent extension
>including its new co-located care-of address.
>
>Is that correct?
>

Almost. The MN has two options. The MN either uses it's co-located care-of
address and registers directly with the GFA (HA field = GFA, COA field =
co-located care-of address, + Hierarchical Foreign Agent extension
including its co-located care-of address), which means that the GFA sends
traffic directly to the MN and the FA is not involved at all. Or the MN
migth decide to use the FA address as COA instead of getting a new
co-located care-of address (HA field = GFA, COA field = FA care-of address,
no Hierarchical Foreign Agent extension). In this case the FA will add a
Hierarchical Foreign Agent extension with its adress, and the GFA will send
the traffic to the FA, who will forward it to the MN.

>Any comments will be good enough to me...
>Thank you in advance.
>

Hope this helps.

/Annika

>BR,
>Dionisios.

---

From: Dionisios Gatzounas <[email-masked]>
Date: Mon, 4 Sep 2000 12:12:38 +0300

Thank you for your time to answer my question.
Your hint was very helpful.

BR,
Dionisios.