[OLSR-users] LQ problems

[Holger Mauermann]

Hi,

I'm using olsrd 0.4.9-pre (Feb 8) and have some problems with the link
quality extension. olsrd prefers the shortest path even if the ETX is
very high... There are three nodes A, B and C. Normally C can reach A
via B, ETX is most of the time at 1.00 for both links A-B and B-C.
However, sometimes C can see A directly with a really bad signal, but
then olsrd sets the route A-C.

C --- B
  .   |
    . |
      A

Here is some debug output from node C:

Node C sees node A (192.168.74.1) the first time, the connection from C
to A via B (192.168.74.2) is very good so far:

--- 19:54:00.98 -------------------------------------- DIJKSTRA

192.168.74.2:1.00 (one-hop)
192.168.74.1:2.07 <- 192.168.74.2:1.00 (one-hop)

--- 19:54:00.98 ----------------------------------------- LINKS

IP address       hyst   LQ     lost   total  NLQ    ETX
192.168.74.1     0.000  0.000  0      0      0.000  0.00
192.168.74.2     0.000  1.000  0      15     1.000  1.00


One minute later the route is changed from C-B-A to C-A even with this
high packet loss and ETX:

--- 19:55:02.04 -------------------------------------- DIJKSTRA

192.168.74.1:28.12 (one-hop)
192.168.74.2:1.07 (one-hop)
(ioctl)Deleting route: 192.168.74.1(hopc 2)
(ioctl)Adding route: 192.168.74.1 gw 192.168.74.1 (hopc 1)

--- 19:55:02.04 ----------------------------------------- LINKS

IP address       hyst   LQ     lost   total  NLQ    ETX
192.168.74.1     0.000  0.533  7      15     0.067  28.12
192.168.74.2     0.000  1.000  0      15     0.933  1.07


Another 30 seconds later:

--- 19:55:31.08 -------------------------------------- DIJKSTRA

192.168.74.1:2.07 <- 192.168.74.2:1.00 (one-hop)
192.168.74.2:1.00 (one-hop)
(ioctl)Deleting route: 192.168.74.1(hopc 1)
(ioctl)Adding route: 192.168.74.1 gw 192.168.74.2 (hopc 2)

--- 19:55:31.08 ----------------------------------------- LINKS

IP address       hyst   LQ     lost   total  NLQ    ETX
192.168.74.1     0.000  0.333  10     15     0.067  45.00
192.168.74.2     0.000  1.000  0      15     1.000  1.00


Some ideas what gets wrong here? All nodes run with LinkQualityLevel 2.

Holger