Group Paging on SPA Phones

[andrew.andy316]

Hi Guys, 

Does anyone know if group paging works over the WAN? 

I've been able to get it working on the LAN but not over the WAN using multicast routing. The closest layer 3 device does not see the phone that is sending as a multicast source. 

Thanks, Andrew

[Dan Lukes]

As long as the multicast packets are delivered successfully from source to destination, it should work.

I don't understand in full the sentence mentioning layer 3 device. But It seems you are saying the source is not sending the multicasts. Well, if packets are not sent then they can't be delivered. It has nothing to do with WAN. The sending phone is just sending multicast. It doesn't know they will be routed later or not.

[andrew.andy316]

Hi,

Thanks for your response. 

The topology is:      [source_phone] -- [access switch] -- [3750X switch stack] -- [2901 WAN Routersx2] -- [Branch Router] -- [Branch Switch] -- [phone]

The 3750 is configured with the vlan interface gateway of the phone. The 3750 is also the first device that is configured for multicast routing. However when the paging number is dialed from the source phone, I do not see the source phone as a multicast source when I check the mroutes. 

Any ideas?

[Dan Lukes · Accepted solution]

Well. You claimed the GP is working on LAN. So the source phone is source of multicast packets (or the GP will not work even on LAN). No phone configuration change is necessary for the purpose of WAN test, so I assume it remain source of multicast packets.

If you are not seeing those packets on 3570X then either:

1. packets are not delivered to it by [access switch]. IGMP snooping capable switches will not switch multicast stream into particular port unless requested by IGMP sent by connected device (or configured statically)
2. packets are delivered to it, but there is something wrong with 3570X configuration.

Or I missed something important ;-)

Unfortunately, I can't help you with configuration of neither [access switch] nor 3570X due lack of experience with such configuration. Ask on other forum.

[andrew.andy316]

No worries Dan.

Thanks much for your help. 

I'll double check some of the things you mentioned.