Hoot & Holler over IP

[Chris Bomba]

I have a hoot n holler over IP configured between 4 sites. One main site w/ a 2600 with 3 T1's connecting the other sites and a 1760 w/ 3 VIC2-2E&M cards. At the remote sites I have the T1's coming into a 1760 which also has one VIC2-2E&M cards. If I generate a tone at anyone of the sites and plug into anyone of the other sites' E&M cards I can hear the tone, just like I am suppose to be, but the tone I am generating is a steady tone and when I receive it, it is intermittent. I am posted an audio recording of the tone I hear at the receiving end. Also if anyone could help me out, please. If you want the configs posted please let me know.

[geoff.belknap]

This can be caused by any number of things. However, the most-likely reason (and easiest to troubleshoot) is a sub-optimal or broken multicast network.

Make sure all of the interfaces involved in the multicast network are configured consistently (ie: ip pim sparse-dense-mode). Ensure that each router has correct *,G and S,G entries for all sites within the group (show ip mroute [group-address]). Verify each router is using the correct RP for the hoot group (show ip pim rp).

Look here for more detailed Multicast Troubleshooting:

http://www.cisco.com/en/US/customer/tech/tk828/technologies_tech_note09186a0080093f21.shtml

You could also have a unicast or multi-cast routing problem.

Verify that the routes to your virtual interfaces (Vif) are stable and not flapping. Also, if the remote (transmit) device has multiple equal paths to the receiver and only one of the paths is multicast enabled you may experience intermittent issues.

If you have a small and simple enough network you might think about using static multicast routes to verify if unicast or multicast routing is a culprit.

If you like you can post the relevant portion of your configs here and I’ll let you know if anything looks suspect.

Hope this helps,

Geoff Belknap

gbelknap@zionsbank.com