I posted earlier about the intercom services on the phones using CM 3.3.3 and have got the intercom between phones working great. I am wanting to play with getting the RTP multicasts working, where I can page a group of phones rather than just phone to phone. I'm assuming that it will simply be changing the URI's from RTPR & T to RTPMR & T and change the address to the multicast address. What I'm not sure of is how to get the phones put into multicast groups. Can anyone point me in the direction of where to look for this information? I am just a developer, so I am not real familiar with the management side of the Call Manager. And this is where I am guessing this is going to be set up, so any help would be appreciated.
Thanks for all your help,
Sorry to bother you all again, I was able to figure out that you don't have to create multicast groups, you just have the phones "listen" on whatever multicast ip you will be transmitting to.
Could you share what you have done to accomplish this? I am a Call Manager Administrator and would love to get this feature rolled out to the enterprise.
You can send me an email on this or post it here so others can see it as well.
Thanks a lot in advance.
I work for a school district and we were researching the possibility of using our IP Phones as an intercom system. The district was kicking around the idea of deploying phones to each of the classrooms in a building and if we are doing that, why not utilize the phones as an intercom and save the money in running cables and speakers to each classroom.
So we downloaded the IP Phone SDK and looked at a few sample programs that they provide. One was the intercom service that allows two phones to talk back and forth via RTP streaming. We simply modified the program so that it would multicast to various phones, or unicast to a single phone. We then gathered the IP's of all the phones and then had the program either multicast or unicast to groups based on IP's. If we only wanted to send a message to First Grade, then the multicast is sent to all IP's that we have designated as First Grade. Or we could do an All-Call, and multicast to all the IP's. This is simply adding a page that they have the option to choose who they want to call and the code then multicasts (or unicasts) to the appropriate IP(s).
There were a couple of extra things that also needed to change for our environment. The sample program required push to talk and we needed handsfree usage for the teachers, and it also required both (or all) parties to press the Exit button when the intercom was exited by one. So we modified it to accomidate these needs.
I also want to add that we have not rolled this out to a school yet, we have only tested it on about 10 phones, so I am not sure how well it will work under those circumstances.
I am also in a school environment and I would be very interested in looking at what you have done. If you wouldn't mind sharing your info with me please drop me an email at email@example.com
There are many products in the market which can do exactly what you specified. Are you open to a COTS solution with a very attractive value?
I too am interested in getting some information on your progress. If you don't mind could you drop me an email at firstname.lastname@example.org ?
Hi, I have tried to get the Intercom feature working without success :( when I select the service (passing the IP address of the phone i want to connect to) the service opened the intercom feature on the phone I am trying to contact but I just get a Error screen on my IP phone. Any Ideas what I am missing?
First you need to figure out what the error is so you can fix it. I use Internet Explorer or telnet to port 80 of the web server to find error messages and see what XML will be sent to the phone. Without knowing what the error is, there really is no way to say what is going on. One thing you might check though, is the user/password you are using associated with both of the phones?
I have written a ASP Application that can do the Multicast (RTP) with Cisco IP Phones. This is an example of do the announcement from Cisco IP Phoen to a set of Cisco IP Phone.
Here following code has been used for multicasting. I also have attached the sample ASP File for refernce. Hope that it wil be useful to all.
var toIPAddr1, toIpAddr2;
toIPAddr1 = getDeviceIP("SEP0008A309F789", callManager, callManagerUserId, callManagerPassword);
toIPAddr2 = getDeviceIP("SEP0002FD3BAB48", callManager, callManagerUserId, callManagerPassword);
// Starting the Transmission
// Start the Receiving on the first terminal
//Start the Receiving on the second terminal
Response.Write("Message Sent to " + phone + " (" + ipAddr + ").
I am confused with the statement:
Transmit a multicast stream to a unicast IP address,
does it work?
Or the statement should be changed to:
By the way, should I have to provision my LAN to
support multicast(IGMP, PIM....). If yes, how can
I do it?
I still don't understand how the message can be
routed to two destination IP phones with multicast
IP address "22.214.171.124".
If it works, its an error in the firmware. RTPMTx should only work for multicast transmission and thus multicast IP addresses. For the transmitting side, the only difference between unicast and multicast is the destination address.
On the receiver side, they have the query the next hop router to join the desired multicast group, and that request propagates between routers unless you have a working path in between sender and receiver. Router will poll group members every now and then, and remove inactive members and adapt the routing tree (that's a gross and perhaps not quite accurate (it's been a while for me)simplification of multicasting).
>By the way, should I have to provision my LAN to
If your phones are all in the same subnet, there shouldn't be any need, but if you go across subnets, then you definitely have to enable multicast which is normally disabled. As for how, I can't help you but there's a group for router programming, so I figure you'd definitely get a good answer there.
>I still don't understand how the message can be
>routed to two destination IP phones with multicast
>IP address "126.96.36.199".
Me neither.. the transmitting phone should do a "RTPMTx:188.8.131.52:port".. then things do make sense.
Is there any way you can repost this script as it has expired on Netpro. Or you could email it to me at email@example.com. It would be incredibly appreciated. :)
Hi there, I know that this posting is a little long in the tooth now but can you please email me this asp file to firstname.lastname@example.org
Is it possible to someone send me a copy of this asp file to my e-mail email@example.com
Thanks in Advanced,
Can I please get a copy of the script as well.
I'm trying to une intercom sample with multiple phones.