Mesh Networking with OLSR

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'''per Interface:''' '''per Interface:'''
 +*HelloInterval
 +
 +*HelloValidityTime
 +
 +*TcInterval
 +
 +*TcValidityTime
 +
 +*MidInterval
 +
 +*MidValidityTime
 +
 +*HnaInterval
 +
 +*HnaValidityTime
 +
 +*LinkQualityMult
 +
 +'''HNA4'''
 +
 +'''I
'''Plugins:''' '''Plugins:'''
-Sample config file:+'''Sample config file:'''
 + 
DebugLevel 0 DebugLevel 0
IpVersion 4 IpVersion 4

Revision as of 21:20, 2 May 2007

Contents

General

What is mesh networking?

Mesh networking is used to route data, voice and instructions between nodes (typically routers). A mesh network typically consists of 2 or (many) more nodes, which exchange information about their connection-status with each other (routing updates), so that every node knows, which path he has to take to reach any other node in the mesh. When a node wants to reach another node that is not directly connected, the traffic flows over other nodes, until the final node is reached (hopping) -each node that the traffic flows through is called a hop.

Why mesh networking?

Mesh networks differ from other networks in that the component parts can all connect to each other via multiple hops. Mesh networks are self-healing: the network can still operate even when a node goes down or a connection drops. The result is a very reliable network.

Benefits of mesh networking

  • self organizing
  • self-healing
  • low system maintenance needed
  • robust due dynamic route recalculation

Disadvantages of mesh networking

  • additional network traffic

The exchange of routing information (routing updates) can produce a lot of traffic-overhead, also every device that takes part of a mesh must have enough cpu/ memory to have an overview of all other routers and how to reach them. (routing table). A full routing table can get very large - as seen in BGP-Routing: a full BGP table needs 2GB of memory (300.000 active routes). There is also a danger of routing-loops that can appear because of weak routing information.

OLSR

General

OLSR is a dynamic linkstate Protocol which collects link data and dynamically calculates the best routes within the network.

Links:

http://en.wikipedia.org/wiki/OLSR
http://www.olsr.org

Parameters

General:

  • IpVersion
  • AllowNoInt
  • Pollrate
  • TcRedundancy
  • MprCoverage
  • LinkQualityFishEye
  • LinkQualityWinSize
  • LinkQualityDijkstraLimit

per Interface:

  • HelloInterval
  • HelloValidityTime
  • TcInterval
  • TcValidityTime
  • MidInterval
  • MidValidityTime
  • HnaInterval
  • HnaValidityTime
  • LinkQualityMult

HNA4

I

Plugins:

Sample config file:

DebugLevel              0
IpVersion               4
AllowNoInt              yes
Pollrate                0.1
TcRedundancy            2
MprCoverage             7
LinkQualityFishEye      1
LinkQualityWinSize      100
LinkQualityDijkstraLimit 0 7.0
LoadPlugin "olsrd_txtinfo.so.0.1"
{
       PlParam "Accept" "127.0.0.1"
}
Hna4
{
}
IpcConnect
{
       MaxConnections  1
       Host            127.0.0.1
       Net 192.168.1.0 255.255.255.0
}
LinkQualityLevel 2
UseHysteresis no
Interface "eth1"
{
       HelloInterval           5.0
       HelloValidityTime       90.0
       TcInterval              3.0
       TcValidityTime          270.0
       MidInterval             15.0
       MidValidityTime         270.0
       HnaInterval             15.0
       HnaValidityTime         90.0
       LinkQualityMult 10.100.2.5 0.5
}
Interface "vlan1"
{
       HelloInterval           5.0
       HelloValidityTime       90.0
       TcInterval              3.0
       TcValidityTime          270.0
       MidInterval             15.0
       MidValidityTime         270.0
       HnaInterval             15.0
       HnaValidityTime         90.0
       LinkQualityMult 10.100.2.5 0.5
}

Setup within DD-Wrt

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