Anup K.Talukdar B.R.Badrinath Arup Acharya MRSVP: A Resource Reservation Protocol for an Integrated Services Network with Mobile Hosts Anup K.Talukdar B.R.Badrinath Arup Acharya

Need for QOS With increase in real-time traffic across the global internet greater and greater demand is being placed on the network. Factors like packet delay,packet loss rate, jitter significantly affect multimedia and voice traffic. The traditional Best effort Service of the internet is not good enough for these. There are basic two models proposed for QOS implementation : Intserv : Network resources are reserved according to the application’s QOS request and subject to BW management policy Diffserv: Network traffic is classified and the network resources are allocated preferentially according to the classification.

Mobility’s effect on QOS With the motion of the mobile node the data flow path changes …….. Packet delay changes Congestion levels in the new network is different A overloaded cell may result in lower bandwidth in the new cell Temporary disruption during hand-offs

Work in this space Loss Profile Application can specify the kind and rate of degradation in data that they can tolerate. use of a hierarchical architecture with a supervisory Host over a set of MSS which is aware of the application’s loss profile and a Loss Profile Transport Sub-layer. Prediction of motion of the mobile host and multicasting packets to the surrounding cells.

RSVP Is used to reserve resources for both unicast and multicast flows. Makes simplex reservations and maintains soft-state Is receiver oriented Two types of messages: Path and Resv Each RSVP message carries a Session which contains the destination IP address, the Protocol Id and dest port number.

RSVP contd A Path message contains the Sender_Template which identifies the particular sender’s packets Sender TSPEC which identifies the traffic characteristics. Path messages install the “path state” in the nodes on the way A Resv message contains A FlowSpec object : a RSPEC that defines the desired QOS and a TSPEC which defines the traffic characteristics A filter Spec: set of senders whom the Resv message is to be forwarded to.

Reservation Model in MRSVP Mobile host can make advance resource reservation. Mobile nodes knows its MSPEC. MSPEC – The set of locations it would visit during the lifetime of connection. MSPEC either from the network or local mobile profile. MSPEC can change dynamically when flow is open. ACTIVE and PASSIVE reservation. BW of passive reservations can be used by other flows with lower QOS guarantees.

Limitations of RSVP No passive reservation. No advance reservation possible from a future location. Sender IP address and port number identifies the sender in the filter specification. If path messages originate from several locations in MSPEC, a receiver cannot determine the identity of the mobile host from sender template.

Overview of MRSVP Proxy agents make reservations. Local proxy agent -> Active Reservation. Remote proxy agent -> Passive Reservation. Two types of path messages. Active path message ->SENDER_TSPEC. Passive path message ->SENDER_TSPEC Two types of Reservation messages. Active Resv -> Active FLOWSPEC and a passive FLOWSPEC if these are merged. Passive Resv -> Passive FLOWSPEC. Additional messages. Join Group, Receiver Spec ,Sender Spec, Receiver Mspec, Sender Mspec, Forward Mspec, Terminate.

Operation Sender Host sends active Path messages Proxy agents send out Passive Path messages Mobile receiver and its proxy agents receive Path messages once the reservation are setup. Mobile host sends out a Resv message for active reservation A proxy for the mobile receiver on receiving a Path message makes a passive reservation on a downstream link and sends a Resv for passive reservation.

Protocol Description Proxy Discovery Protocol Proxy agent is a MRSVP capable router Default gateway Capable of making passive reservation Capable of notifying the results to the host PDP uses foreign agent care-of-address from Mobile IP Two messages Remote Agent solicitation Remote Agent Advertisement Home subnet-HA as proxy Foreign subnet - foreign agent care-of-address as proxy address

Reservation of routes Mobile sender Sender-anchor node –P the local proxy agent during flow initiation. Flow F split into: A unicast flow from mobile sender and its remote proxy agents to P A unicast or multicast flow from P to destination Mobile Receiver –Multicast flow Mobile host sends Join-group with multicast address of the group DST and the R_SPEC Remote proxy agent joins the group Paths of both active and passive reservation setup.

Reservation of routes (contd) Mobile Receiver Unicast flow Using Unicast routing Designate a receiver -anchor node Passive reservation between this node and remote proxy agent ,active reservation between it and the host Can use the mobile sender as the receiver anchor node too. Using Multicast routing using a multicast routing using the multicast address allocated to a mobile host

Reservation Routes Join_group C5 C6 MH2 Active Resv Passive Resv Active Path MH2 Active Resv Passive Resv N9 Passive Path N8 N1 N3 N2 N7 N5 N6 N4 C4 C1 C2 C3 MH1

Reservation Setup On receiving the DST address the mobile sender M establishes the split connection: It sends Sender-Spec and Sender-Spec to the sender anchor node -P Sender-anchor node checks if already flow has been setup . If so returns that dest port no. else allocates new one p. Sender-Anchor node sends a message containing the unicast address (P,p) and the sender TSPEC and ADSPEC to to M and its proxies Next it creates a psuedo-header for M identified by (P,m) with destination address DST.

Other issues Merging Active and Passive reservations Active and Passive reservation are merged e.g. at a sender-anchor node SENDER_TSPEC from mobile sender and its remote proxies are merged to create a single TSPEC to be forwarded Switching between Active and Passive Reservation Soft state : Proxy agents have an expiry time with the sender/receiver spec that they receive

Design II Changes the Path messages to include a RSVP object called the MOBILE_ID MOBILE_ID-Home IP address and RSVP source port of the mobile sender Source and Sender –Template IP address of the Path message contains this IP address On receiving this message a Path state with this Mobile_ID object is recorded In RESV messages this object is used to identify the previous hop

Conclusion /Comments This is the first complete signaling(I believe) mechanism to be proposed for implementing QOS in mobile environments The scalability and security issues in MRSVP to be investigated Questions of Scalability are really important as the amount of state to be stored per connection in each router is large.