Ahmad, I was referring to the IP address used as a session identifier which can be the same as or different from the IP address used as a routing address of the MN interface. To identify the network session, a TCP session for example uses source-destination IP addresses and port numbers in the socket to uniquely identify the network session between the MN and CN.
Referring to the IP address used as session identifier then: An MN can be running multiple IP application sessions. Each of these IP application sessions uses an IP address. The different IP application sessions run on the same MN can have the same or different IP addresses. The use case of using different IP addresses for different IP application sessions by the same MN is as follows: The mobile node has acquired an IP (routing) address as it attaches to a network. With this IP address, it can run multiple network application sessions, say a telnet session and a VOIP call session. When it then moves to a different network, it will acquire a new IP (routing) address from the new network. If it now starts a new application session(s) after it has already moved to the new network, it is easier to just use this new IP address as the session identifier for these application sessions(s). (so that the IP address used in session identifier is the same as the routing address.) This is the reason for REQ2. The use case here is that for the mobile host, the VOIP call session can continue after moving to the new network. This session will need to use the previous IP address as the session identifier. Then the mobile node is now using 2 different IP addresses (used as session identifiers): the VOIP session(s) which had started in the previous network and which has not yet terminated will use the previous IP address; the new application sessions that started after the MN has moved to the new network can use the new IP address. H Anthony Chan -----Original Message----- From: Ahmad Muhanna [mailto:[email protected]] Sent: Friday, December 21, 2012 10:13 AM To: h chan; Jouni Korhonen; [email protected] Cc: Julien Laganier Subject: RE: [DMM] [DMM Requirements] [WAS Call for WG Adoption of a "current practices and gap analysis" document Anthony, Thanks for offering me to propose text, however, before getting into that, I would like to make sure that we understand the details and we are on the same page. Good explanation! Please see some follow up questions below: 1. Do you mean an IP session is an IP address that is associated with a specific application that is hosted on a specific device (Mobile node) while being anchored at a specific Node in the network? 2. In addition, are you saying that every application is using a different IP session? Or multiple applications can use the same IP session? 3. I assume from your explanation, a specific device (mobile node) can have multiple IP sessions that are hosted on that device, right? 4. Moreover, you seem to suggest that the same device can have multiple IP sessions with different mobility requirements. Correct? Hopefully you do not mind the clarification. Many thanks in advance! Regards, Ahmad -----Original Message----- From: h chan [mailto:[email protected]] Sent: Thursday, December 20, 2012 12:43 PM To: Ahmad Muhanna; Jouni Korhonen; [email protected] Cc: Julien Laganier Subject: RE: [DMM] [DMM Requirements] [WAS Call for WG Adoption of a "current practices and gap analysis" document Ahmad, The mobile nodes are running network applications (IP sessions). Mobility can be thought of as being provided to the mobile nodes. Alternatively it can be thought of as being provided to the applications. I think the difference is shown in the following: IP mobility support is not always needed by all network applications or at all times. Web-browser does not need it. A laptop often does not move during the life of an IP session. So the flexibility to provide and not to provide mobility support is needed. What REQ2 is trying to avoid is to provide mobility support to the mobile nodes such that it is provided by default to all the applications when the mobility support is provided to the mobile node. So I would think of providing mobility support to the applications. Please feel free to suggest text changes if the REQ are not clear. H Anthony Chan -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ahmad Muhanna Sent: Thursday, December 20, 2012 11:35 AM To: Jouni Korhonen; [email protected] Cc: Julien Laganier Subject: Re: [DMM] [DMM Requirements] [WAS Call for WG Adoption of a "current practices and gap analysis" document Hello Jouni and All, I am trying to catch up with the DMM working group. I must admit that I was NOT able to follow all the discussions but I felt before being able to address the current practice and gap analysis, I needed to understand the proposed requirements. So, I went ahead and read the Requirements draft one more time and I found a couple of things that are essential to be clarified in order to have a solid ground for hopefully a solid proposals and solutions. REQ1: Distributed deployment IP mobility, network access and routing solutions provided by DMM MUST enable distributed deployment for mobility management of IP sessions so that traffic does not need to traverse centrally deployed mobility anchors and thus can be routed in an optimal manner. [Ahmad] In order to understand this requirement or may be in order for this requirement to be clear and makes sense, I would like to understand what is meant by IP session(s) in this context? And may be its relationship to the mobile node. REQ2: Transparency to Upper Layers when needed DMM solutions MUST provide transparent mobility support above the IP layer when needed. Such transparency is needed, for example, when, upon change of point of attachment to the Internet, an application flow cannot cope with a change in the IP address. Otherwise, support for maintaining a stable home IP address or prefix during handovers may be declined. [Ahmad] This a simple requirement that is phrased in a way that makes it a little more complex than needed. However, my question here is: how this requirement is related to the "IP session(s)" mentioned in the REQ1? I believe it is fundamentally important to understand the relationship in order to be able to move forward. In addition, I believe the remaining requirements sort of straight forward and clarification of the above two points is essential (at least to me) Thanks for all the help! Regards, Ahmad -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jouni Korhonen Sent: Wednesday, December 19, 2012 2:25 PM To: [email protected] Cc: Julien Laganier Subject: [DMM] Call for WG Adoption of a "current practices and gap analysis" document Folks, We are unfortunately slipping our milestone, our (chairs) apologies for that. The next step is to select a "current practices and gap analysis" document to serve as the basis for the future WG document. We consider two documents on this topic to choose from: [1] draft-zuniga-dmm-gap-analysis-02 [2] draft-liu-dmm-best-practices-gap-analysis-01 and we as a WG need to decide which one is going to form the _basis_ for the WG document. Please voice your preference either for [1] or for [2] on the mailing list. We would appreciate if you can also provide a one-liner justification for your selection. The chairs will determine if there is (rough) consensus from active WG participants to proceed with selecting one document against the other. The call starts today 19th Dec 2012 and ends by 10th Jan 2013. We have a longer three week call now due the holiday season in between. - Jouni & Julien _______________________________________________ dmm mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmm _______________________________________________ dmm mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmm _______________________________________________ dmm mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmm
