[Freifunk-Bonn] Packet-Loss-Peaks in a Freifunk-Network

[Jan Lühr]

Hello folks,

we spent some effort in measuring the stability on our freifunk-network. 
The networt itself consists of two networks.
- Tinc-VPN, batman-adv 2011.2.0
- fastd-VPN, batman-adv 2012.4.0

The fastd-network has two gateways (kif and fastd3) and two nodes. Each node is connected to both gateways. (Example output of batctl o see below)

Please take a look at: 
http://kbu.freifunk.net/index.php?title=Statistik#Ping_innerhalb_des_Freifunknetz
While the first chart shows the stability of a node connected directly via tincy, the later ones use fastd.

- Chart 2 shows kif -> node1
- Chart 3 shows fastd3 -> node1
- Chart 4 shows kif -> node2

We noticed a few, unusual things:
-> regardless of the link tested (kif or fastd3) and regardless of the node (node1, node2) small interruptions (loss-peaks) are appearing.
-> These peaks appear almost synchronous, a few "noise" comes from different vpn-links and node-wan-uplinks.
-> Since all links are wired, radio-noise won't have an impact
-> The losses appear in batman-adv 2011.2.0 as well as in batman-adv 2012.4.0.
Thus I suspect that batman-adv is triggering theses interruptions. 

Have you notice same problems in past? Is there a way to fix these outages?

Thanks,
Keep smiling
yanosz

# batctl o
[B.A.T.M.A.N. adv 2012.4.0, MainIF/MAC: wlan0-1/b2:48:7a:cb:2d:59 (bat0)]
  Originator      last-seen (#/255)           Nexthop [outgoingIF]:   Potential nexthops ...
             vpn3    0.130s   (255)              vpn3 [  mesh-vpn]:               kif (198)              vpn3 (255)
              kif    0.280s   (255)               kif [  mesh-vpn]:              vpn3 (  0)               kif (255)
            node1    2.700s   (225)               kif [  mesh-vpn]:               kif (225)              vpn3 (225)
            node2    3.110s   (223)               kif [  mesh-vpn]:               kif (223)              vpn3 (225)