The Snom PA1 and Snom Phones are capable of sending and receiving Multicast audio streams for purpose of paging. In order to relay a Multicast from the phone, you must configure a Multicast Relay address. On the phones that will receive the Multicast audio/Page, you must configure the Multicast Listener, using the Multicast Relay address, and enable Multicast Support.


Setting Up Multicast Relay


The first step is to properly choose a valid and available Multicast address for your Multicast Relay address/Page.



The valid range of Multicast addresses in the administratively scoped IP version 4 (IPv4) multicast address space is the range from 239.0.0.0 through 239.255.255.255. Please refer to RFC 5771 to see the reserved Multicast addresses  https://tools.ietf.org/html/rfc5771  also https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml


Once you have chosen a valid and available Multicast address to use, you must select an available non-reserved listening port. See RFC 1700 for a list of available listening ports https://tools.ietf.org/html/rfc1700


A valid Multicast and listening port combination would be something like 239.255.255.245:5555


Configure the PA1 as a Multicast Relay for Pages (firmware version 8.7.5.x and 8.9.3.xx)


After you have configured the PA1 with an extension on one of the four available Identities, you can configure that extension for Multicast Paging. 


1. From the Web User interface of the PA1, navigate to the Identity you want to configure.

2. Select the RTP tab

3. Configure the Multicast Relay Address and listening port. i.e. 239.255.255.245:5555

4. Select Apply and then Save to save the settings change. 


(note: this option is only available on the Snom PA1)


Configure the phone to be a Multicast Relay for Pages (firmware version 8.7.5.x and 8.9.3.xx)


Alternatively, you can configure a Snom phone to be a Multicast Relay for the purpose of paging to all Snom devices that are listening for the Multicast page.


1. From the Web User interface of the Snom phone navigate to Function Keys section.

2. Select an available function key to configure.

3. Configure the context which is either Active for the active line or choose a specific Identity.

4. Next, configure the Type and select Multicast

5. In the Number field enter the Multicast Relay Address and listening port. i.e. 239.255.255.245:5555

6. Add a short text description which will appear on the LCD of the phone if you are configuring P1 - P4 on certain phones.

7. Click Apply and then Save to save the settings change.



Configure the Snom PA1 or Phones to be a Multicast Listener (firmware version 8.7.5.x and 8.9.3.xx)


Once you have completed the previous tasks you must configure the PA1s and Phones that will receive the Multicast Paged audio.


1. From the Web User interface of the PA1 or Snom phone navigate to Advanced.

2. Navigate to the SIP/RTP tab and scroll to the bottom of the page.

3. Enable Multicast Support and enter the previously configure Multicast Relay address in the IP address field.

4. Click Apply and then Save to save the settings change.



NEW! Configure the Snom Phones to be a Multicast Listener (firmware 10.15.1.0 and higher)


A new feature has been introduced with the 10.x.x.x version of Snom firmware to define a name for 10 configurable page zones. These named zones can that be accessed from the Phone's LCD in a List view for the purpose of being a relay for the available Multicast Page Groups



 



Configure the phone to be a Multicast Relay for Pages (firmware 10.15.1.0 and higher)


1. From the Web User interface of the Snom phone navigate to Function Keys section.

2. Change the F4 Soft Key from Help to Multicast Zones

3. Give it a short text name. The default value is "M-Page"

4. Apply the change and Save.



5. From the Phone User Interface, press the corresponding key for the Info context-sensitive key 



6. This will bring you to an option for the M-Page screen



7. Select M-Page and this will present you with your list of Multicast Zones



8. You can scroll through the list with the circular navigation key on the phone's keypad. Use the checkmark or corresponding number 1 - 10 to select and X to cancel.


 

Test and troubleshoot.


Make a test page to ensure it is working. If it is not, reconfirm your configuration and settings are correct. If they are, use PCAP trace feature of the PA1 and Phone to determine if the Multicast is being properly sent by the relay and received by the listeners. Save the PCAP trace and view it in Wireshark. If the Multicast is being sent, but it is not being received, then it is possible the Network/Switches are the issues. The Multicast will not propagate across Subnets and VLANs. The relay and listeners must be on the same logical Subnet/Broadcast Domain. IGMP Snooping can also prevent the Multicast from being propagated to the Switch ports the listeners are connected to. Correct those issues if they exist and re-test.



Settings

http://wiki.snom.com/Settings/mc_address

http://wiki.snom.com/Settings/multicast_listen

http://wiki.snom.com/Settings/multicast_relay_address

http://wiki.snom.com/Settings/fkey/multicast


For Multicast Audio Streaming

http://wiki.snom.com/Category:HowTo:Multicast_Audio