VOIP Lines and Allow Direct Media Path

[itsthephoneguy]

I have a six site mpls star configuration. Three sites are "main sites" with PRIs and DIDs for the other three remote locations. In other words, the three remote location backhaul over VOIPs to the other sites on a one to one basis to receive calls. 80% IP phones (5610s).

Calls from one site to another would ring each other and, after connecting, would hang with dead air. I removed Allow Direct Media Path from all of the voip extensions at all locations. This cleared up the site to site dead air issue. However, they are experiencing something new. If a call between two sites is placed on hold, the call cannot be picked back up. They experience the same type of dead air issue. I still have Allow Direct Media Path checked on the VOIP lines themselves. Should I remove this? If so, what is the reasoning behind it? How does it interact with the call?

 

[superikey]

I am having this same issue at a client. I am going to try turning off direct Media Path on the VOIP Trunks. Please try the same and keep us all posted.

Isaac Braca
CTO / ICCS & Co., LLC.
Email: braca@iccsllc.com

ICCS, Your Premier IT Partner, is a NYC Based Avaya Business Partner and IT Consulting Firm.

 

[intrigrant]

Turning the direct media path off is a bad option, for each ongoing call you need VCM resources.

If IP calls can be established but no speech then your phones are routing the IP Packets to the wrong router.

Reconsider all IP settings of your phones, router settings and firewall settings, each IP set must be able to connect to any IP set in the WAN

 

[jameshen]

We experienced these issues with our 7 site SCN (3.1.65) There are a few settings that must be set correctly for everything to work.

It kinda hinges on whether or not you're using VLANS. We do not using VLANS. Baically, if you're not using VLANS, change the 802.1Q setting on the IP phones to "Off" and the voice will work between sites. Do not un-checked the "DEFAULT" setting of "Allow Direct Media Path" on the extensions. (That just causes the subsequent hold issue.)


So, if you're not using VLANS, these things need to be in harmony:

1. IP PHONES: Set 802.1Q to "Off" (By pressing * to program when the phone boots up.)

2. MANAGER - Extensions: Enable the default setting of "Allow Direct Media Path" on all VoIP extensions.

3. Manager - Lines: We currently have "Allow Direct Media Path" enabled on our VoIP lines. (However, I believe it will work either way assuming that the above 2 settings are correct.)

 

[itsthephoneguy]

How will turning off 802.1Q effect QOS?

 

[janni78]

It shouldn't affect it at all since it's a VLAN protocol.
Although I don't see why having it set on auto on your IP phone should cause trouble. Never needed to touch that setting.

 

[jameshen]

The Layer 2 and Layer 3 signaling options are still available on the phone after turning off 802.1Q. Therefore, I'm assuming that it just disables the Virtual LAN encapsulation.

Incidentally, I noticed in the Avaya's IP_Phone_Installation.pdf, the instructions for using static IP addressing actually tells you to turn off 802.1Q. Our installers also recommended turning the setting off if we didn't use Virtual LANs.

The setting doesn't seem to cause an issue within the local site, just when you attempt to call across a VoIP line between sites. Turning off 802.1Q also slightly speeds up the phones boot sequence. As I recall, with it turned on, the phone does an initial DHCP request on the LAN, then attempts to find / acquire an IP address on the VLAN.

 

[itsthephoneguy]

jameshen

Thanks for all of your input (both topics). I will give this a try and post the results.

Thanks again...