MoH - Skype, AudioCodes and an SIP Carrier

Troubleshooting an MoH issue today, where a SfB client would places a PSTN caller on hold, and the PSTN caller would get no MoH.  

SBC connection to PSTN was via a SIP trunk.

What I found was:
When call placed on hold from SfB client the INVITE had sdp of a=sendonly
This was received by the SBC and the AudioCodes "Remote Hold Format" on the IP Profile associated with the Skype side was set to "Transparent"

The "Remote Hold Format" on the ITSP side was also set to "Transparent"

In this instance the INVITE was forward to the carrier with an a=sendonly attribute.

But the ITSP would reply with a "200 OK" but the attribute was set to a=inactive.  This effectively shutdown the media path and the ITSP would not get the MoH stream from the SBC.

The Fix:
After reading the manual for the AudioCodes SBC and seeing what all the values in the "Remote Hold Format"

• Transparent = (Default) Device forwards SDP as is.
• Send Only = Device sends SDP with 'a=sendonly'.
• Send Only Zero ip = Device sends SDP with 'a=sendonly' and 'c=0.0.0.0'.
• Inactive = Device sends SDP with 'a=inactive'.
• Inactive Zero ip = Device sends SDP with 'a=inactive' and 'c=0.0.0.0'.
• Not Supported = This option can be used when the remote side does not support call hold. The device terminates call hold requests received on the leg interfacing with the initiator of the call hold, and replies to this initiator with a SIP 200 OK response. However, call retrieve (resume) requests received from the initiator are forwarded to the remote side. The device can play a held tone to the held party if the 'SBC Play Held Tone' parameter is set to Yes.
• Hold and Retrieve Not Supported = This option can be used when the remote side does not support call hold and retrieve (resume). The device terminates call hold and call retrieve requests received on the leg interfacing with the initiator of the call hold/retrieve, and replies to this initiator with a SIP 200 OK response. Therefore, the device does not forward call hold and/or retrieve requests to the remote side.

When the "Remote Hold Format" on the IP Profile associated with the ITSP was change to Hold and Retrieve Not Supported, the behavior of the SBC was changed to that once it received the INVITE with a=sendonly, it did NOT forward to the ITSP, so the media path was never altered from SBC to ITSP, and MoH was then played to the PSTN caller..

AudioCodes FXS

Lately have been migrating fax to FXS ports on M800's

Seems every time i need to look through logs I forgot what the message written to the file is, this post is just a dump of log messages so that I don't ave to go looking for things all the time..

+++++++++++++++++++++++++++++++++++++
recv <-- OFF_HOOK: FXS sending off hook message to gateway
recv <-- DIGIT(x): x is the digit received



+++++++++++++++++++++++++++++++++++++

AudioCodes AD Authentication

Been playing with AD authentication and AudioCodes SBC with firmware 7.2 and found a few things, thanks to Dave for the help..

If LDAP is enabled but not configured correctly you will get locked out of the SBC, not even the local SBC accounts can access the gateway.  So make sure that you don't close your browser window in the middle of the config, or even let the timeout for access be reached...

Under "Setup --> IP Network -->Radius & LDAP"

Select "LDAP Settings"

Change the "LDAP Service" to enabled, and  change the "LDAP Authentication Filter" to (sAMAccountName=$).  Making sure that the () are included

As always the lighting bolt icon means that a reboot is required.

Under "LDAP Service Groups"

Select "New" and complete with the following details, make sure that "Type" is set to Management

Under "LDAP Servers"

Select "New" and enter the required details:
LDAP Server Group --> >name of the server group from "LDAP Server Group"
LDAP Password is ALWAYS --> $
LDAP Bind DN is --> $@'domain.com'
Management Attribute --> memberOf
LDAP Server IP --> IP Address of DC

Under LDAP Servers, select "LDAP Servers Search Base DNs"

Select "New" and enter the base DN to start searching within AD.

Under LDAP Servers, select

Select "New" and enter the AD group to check for membership.

Troubleshooting

• "LDAP Authentication Filter" to (sAMAccountName=$).  Make sure there are no "quotes" around the entry in the WebGUI
• Under the AdminPage update the "LDAPDEBUGMODE" value to be 3 (0 default, 3 highest level) then details can be checked in syslog.

AudioCodes vSBC Initial Configuration

Another quick post so that I remember how to complete the AudioCodes vSBC initial configuration..

After the import of the OVF file the system will boot with a default IP address of 192.168.0.1.

To run the Configuration Wizard complete the following:
Login using the default username and password:
Admin/Admin

Enter the privileged command level:
enable

Password is default: Admin

configure-wizard

select "Yes" to complete

Select "No" for the "Do you want to configure Web-CLI User parameters?

Select "Yes" to "Do you want to configure OAMP Network Settings?"

Enter VLAN ID:

Enter IP Address:

Enter prefix length:

Enter default gateway:

Enter primary DNS server:

Enter secondary DNS server:

Select "No" to "Do you want to configure SNMP Network Management?"

Confirm the settings just configured, via selecting "Yes"

The system will then restart.

After the reboot has completed, the system should have the IP address configured.

AudioCodes FXO to Lync Configuration

Was setting up an FXO analog port for an in-dial today, with an AudioCodes Mediant 800, has some issues with getting the FXO to make and receive calls.  After a few email with support at VExpress finally got it sorted.

The basic configuration of the Mediant 800 is much the same as all their other gateways, the FXO port needed a little tweaking that I hadn't been able find in any other documents.

The only additional configuration that was required was under "VoIP --> GW and IP to IP --> Analog Gateway --> FXO Settings" and under "VoIP --> GW and IP to IP --> Analog Gateway --> Automatic Dialing"

FXO Settings
Change the "Dialing Mode" to One Stage

Automatic Dialling
Then we had to setup the Automatic Dialling you just need to set the phone number that corresponds to the FXO line that is being configured.

UPDATE:

So with this configuration we were seeing some issues with call quality on the Lync end.  The PSTN caller could hear with no issues at all.  It turns out that the Mediant with FXO ports needs to have the earth cable installed, once this was installed the call quality issues have gone.