Witnessing a strange issue in our setup.
I will try to sum up everything as below:
* We have 3 ASR ( ISP Managed) on which we had terminated 3 ISP MPLS links.
* 6500 is connected with those 3 ASR.
* Out of those 3 links, 2 are in production in load sharing mode ( BGP multilink)
* No problem or even no intermittent problem witness as long as we run on 2 ISP links
* As soon as we introduce 3rd link, we start getting all sort of problem with Voice call issues to ghost call to one way voice, etc.
* Voice is already market with EF on IP Phone and is honoured and put in priority queue on 6500
* No drops observed to ASRs or even remote edge sites.
* No collision, CRC or any other errors witnessed.
* ISP says no problem observered at their end.
I have now run out of ideas to troubleshoot the issue. I definate think issue should be be with that particular 3rd ISP link; however ISP says to provide them proof for further action.
Any directional or conceptual help highly appriciated.
PS: Due to NDA, I won't be able to provide any command outputs, however I can check anything particular you need and give you feedback.
Message was edited by: smitesh kharecha
The only thing i can think of is the that the third ISP is not honouring your markings correctly.
I am assuming that with your existing ISPs you have QOS provided by them within the MPLS cloud ?
So even though you may not be seeing any drops at the remote end that does not mean they are being delivered within the time contraints required by VOIP.
I had already checked by making basic ACL matching packets for EF and tried end to end extended ping, which were succesfull.
I confirm EF is honoured in telco cloud.
What else can be the reason.
I doubt this could be the problem as you are already running ovet two separate ISP links but i was wondering about packets arriving out of order because you have multiple links. Out of order packets can significantly affect voice packets so i wonder if this could be an issue.
Like i say, unlikely, but just suggesting possible causes.
Just a clarification, all 3 links are from same ISP.
As far as your doubts goes over packet arriving out of order, even I doubted the same, however I'm still wondering how to check that and what action as such can be taken to rectify out of order packet arrival issue.