Our branch office has an EOIP tunnel back to our main office. All the VOIP desk phones at that location are having latency issues. Our ISP in this case will prioritize VOIP traffic but due to the EOIP tunnel it is not being recognized as such and therefore being tossed in with P2P and everything else.
If we put 802.1p tags on the EOIP packets saying that they are highest priority, the ISP will give them higher priority and theoretically solve our problem.
Issue is, how do I flag the EOIP traffic?
I have dug around a bit but searching for 802.1p does not even get any hits on the MT website and gets very few hits here.
savage
March 2, 2009, 10:01pm
2
Because you’re searching for the wrong thing I suppose. It’s not a port, it’s a protocol. Protocol 4 ip-encap, or protocol 94 ipip
Hmm? I do not understand your answer at all. It does not appear to be relevant to my inquiry. It certainly gets me no further toward my solution.
I can search for IPIP for sure but that tells me nothing about how to setup changing the TOS bit.
I have done some more digging.
It seems I may need a mangle or filter rule that changes the TOS to:
ToS 0xb8 = 10111000 = 184
But ROS will not accept either 184 or 64 (or any other of the numbers). The field simply says “New DSCP (TOS)” but will not accept either value.
Plus I am unsure of what type/config of mangle or filter rule I need. I will keep digging here but some help would make this much easier.
savage
March 2, 2009, 10:31pm
4
Granted, havent looked at this with a packet sniffer to see whether the TOS is actually set or not (that’s a different story all together)
DSCP:
[cknipe@WMEO01-CORE01] > /ip firewall mangle print stats where dst-address="196.25.1.1"
Flags: X - disabled, I - invalid, D - dynamic
# CHAIN ACTION BYTES PACKETS
0 prerouting change-dscp 256 4
[cknipe@WMEO01-CORE01] > /ip firewall mangle print detail where dst-address="196.25.1.1"
Flags: X - disabled, I - invalid, D - dynamic
0 chain=prerouting action=change-dscp new-dscp=5 src-address=192.168.1.0/24 dst-address=196.25.1.1
[cknipe@WMEO01-CORE01] >
FYI: http://www.cisco.com/en/US/tech/tk543/tk757/technologies_tech_note09186a00800949f2.shtml
I’m running 3.20, seems to be working fine?
Ah that was much better, thank you!
I am guessing based on the example, that despite the ROS interface saying DSCP it actually wants the number in 802.1p format. ie the 5.
That little cut and paste will save me hours of effort!
If anything it is a huge starting point.
Thanks!
I think I have it all working. I told it to simply flag all packets being sent to the other RB with 5.
I had to set the rule to be a postrouting as opposed to a prerouting otherwise nothing hit the mangle rule.
I now see traffic hitting the mangle rule, I just have to figure out if the ISP at the branch office is respecting the flag now.
We are the ISP at the head office end so that end is no issue . . .
