MULTICAST PROTOCOLS EVALUATION IN WIRELESS DOMAINS

1
MULTICAST PROTOCOLS EVALUATION IN WIRELESS DOMAINS

• R. Kornblit E. Schwarzmann
• Instructor Nadav Lavi

Homepage - http//comnet.technion.ac.il/cn02w04/
2
Project Goals
Classify existing multicast protocols according
to their suitability with a wireless environment,
based on data collected from ns2 simulations and
theoretical analysis.
3
Overview

• Thorough study of multicast protocols (existing
  and proposed) and wireless protocols
  (including Mobile IP)
• Study of the ns2.
• Running various simulations (incorporating
  multicast and wireless scenarios with ranging
  characteristics)
• Analyzing simulation traces (in terms of
  packet loss, delay , network overhead, etc.)

4
NS2
ns2 stands for network simulator (version 2) Ns
is a discrete event simulator targeted at
networking research. Ns provides substantial
support for simulation of TCP, UDP, routing, and
multicast protocols over wired and wireless
networks. Languages used with ns2 C (To
implement protocols) OTcl (To write simulation
scripts)
5
NS2 structure

• Nodes - the hardware entities in a network.
• Agents - the software entities which are on
  these nodes
• (TCP, UDP)
• Links - connect the nodes in the network.
• links can be simplex / duplex
• Traffic generators -
• Source - An agent which is the originator of
  packets
• Sink - An agent which is the destination for
  these packets.

6
NS2 (cont.)
Schematic of hierarchical wireless Base Station
node
7
Multicasting in NS2
Implemented protocols CtrMulticast - similar to
PIM sparse mode DM - has two
options PIM dense mode/DVMRP BST
- a bidirectional shared tree multicast
protocol Additional protocols SRM (scalable
reliable mcast) - works with older versions
of the simulator. MOSPF added patch, is not
fully compatible.
8
Mobile IP simulation example
Source 0 sends to Mobile Host 4 via Home agent 2
FA
HA
HA
FA
MH
MH
MH
Legend Node 0 Source Node 1 Router Node 2
HA (Home Agent) Node 3 FA (Foreign Agent) Node
4 MH (Mobile Host)
At Home Domain
At Foreign Domain
9

• The problem
• Combining the two features (multicast wireless)
  
• the simulator doesnt support that task!
• Possible solutions
• Simulate the movement pattern by simultaneous
  leave-group and join-group to different
  nodes.
• Consult with major contributors of ns2 code, who
  have dealt with similar problems.
• Change the source code of the ns2 to fit our
  specific needs.

10
Current status

• Movement simulation
• created various scenarios for all 4 implemented
  protocols. In the process of analyzing results
  and drawing conclusions.
• Contributed codes
• Discovered implementations of several
  protocols
• SRM incorporates mcasting with movement, partly
  compatible with older versions of the simulator
  (ns 2.16)
• Mobiwan, Xcast, DDR, MMP implemented, but do
  not really meet our needs (IPv6)
• Changing the source code
• In the process of understanding the required
  changes.

11
Simulation example Typical wireless movement
(join-leave method) on a tree based topology.

• Network specifications
• No. of nodes 100
• Max no. of branches 5
• Average depth in hops 4.5606 (with variance of
  0.3069)
• Movement pattern local (90 level one moves)
• Access point attached to the wireless node
• Source (node 0)