TELECOMMUNICATIONS NETWORKS II
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TELECOMMUNICATIONS
NETWORKS II
COURSEWORK RESIT
AUGUST 2023
1. The challenges facing mobile network architectures in the application- and service-centered future are indeed tremendous, as data demands of mobile users are already stressing the existing network. During the lectures we have discussed various micro mobility solutions such as hierarchical Mobile IPv6 and Fast Handovers for Mobile IPv6. Existing network-layer mobility management protocols have primarily employed a mobility anchor to ensure connectivity of a mobile node by forwarding packets destined to, or sent from, the mobile node after the node has moved to a different network. The mobility anchor has been centrally deployed in the sense that the traffic of millions of mobile nodes in an operator network is typically managed by the same anchor. This centralized deployment of mobility anchors to manage IP sessions poses several problems. IETF has proposed the Distributed Mobility Management (DMM) framework [1] to tackle such issues. Explain the motivation behind the introduction of DMM technology, how this compares with previous techniques and the DMM options available to operators [2].
[1] D. Liu, JC. Zuniga, P. Seite, H. Chan, CJ. Bernardos, Distributed Mobility Management: Current Practices and Gap Analysis, IETF
RFC 7429, January 2015
[2] S. Jeon, S. Figueiredo, R. L. Aguiarand H. Choo, Distributed Mobility Management for the Future Mobile Networks: A
Comprehensive Analysis of Key Design Options, IEEE Access, vol. 5, pp. 11423-11436, 2017.
2. TCP has remained mostly unchanged for more than 20 years, even as its uses and the networks on which it runs have evolved significantly. TCP cannot use multiple paths which is possible to utilize in modern networks and in fact, a TCP connection cannot even be load balanced across more than one path within the network, because this results in packet reordering, and TCP misinterprets this reordering as congestion and slows down. Multipath TCP (MPTCP) [1], [2] is an evolution of TCP that allows it to run over multiple paths transparently to applications. Discuss in detail the motivation and rational of introducing the MPTCP and explain in detail the operation of the protocol and how this compares with the plain TCP protocol. For further resources please use reference [3] that provides further information of the proposed protocol.
[1]A.Ford, C.Raiciu, M.Handley, and O. Bonaventure, TCP
Extensions for Multipath Operation with Multiple Addresses, IETF RFC 6824, January 2013
[2] Christoph Paasch and Olivier Bonaventure, Multipath TCP Decoupled from IP, TCP is at last able to support multihomed hosts, ACM Queue, vol.12, issue 2, March 2014
3. Mobile Ad hoc Networks (MANET) are self-configured and infrastructure less networks with autonomous mobile nodes. Due to the high flexibility, these kinds of networks are heavily used in use cases such as rescue operations, military missions, and sensor networks. More specifically, MANETs are networks with nodes that are mobile and can be connected dynamically and arbitrarily making the topology very flexible. The communicating devices are auto configurable and there is no need for extra infrastructure. Each of the network activities such as discovering the topology, sending messages or routing messages is performed by each node in the network. We have discussed during the lectures the Dynamic Source Routing (DSR) protocol [2], however another protocol which is widely used in such environments is the Ad hoc on-demand Distance Vector (AODV) protocol [1]. AODV is a reactive protocol that belongs to the class of Distance Vector Routing Protocols. It starts a route discovery process only when a node has data packets to transmit and there is no route path (or when the route is stale or broken) towards the destination node. The routing table of each node contains the necessary information about the route from source to destination and sequence numbers to avoid loops. Discuss in detail the operation of AODV protocol and how it compares with the DSR protocol. Discuss pros and cons of AODV versus DSR and explain use cases where you expect one to outperform the other.
[1] C. Perkins et al., Ad hoc on-demand Distance Vector, RFC 3561, July 2003
[2] D. Johnson et al., The Dynamic Source Routing Protocol (DSR) for Mobile Ad Hoc Networks for IPv4, RFC 4728, February 2007
2023-07-24