When I was troubleshooting some hosted LiveMeeting connectivity issues for a client, I decided to run a sniffer trace of the whole process. It turned out to be really useful to see how the client connected – especially what ports and protocols are used. Below is a step-by-step of what I saw happening. If you do the same, you’ll see different IPs and servernames (MS uses pools), but generally see the following traffic pattern:
1 User clicks on meeting invite from within Outlook
2 Traffic to and from exchange
3 Browser opens www.livemeeting.com page
4 DNS query for www.livemeting.com
5 DNS reply with 204.176.46.146 – LiveMeeting Portal Server
6 HTTPS negotiation between client and server
7 Certificate/key presented and verified
8 HTTP redirect to www0.livemeeting.com – LiveMeeting Portal Server
9 DNS query for www0.livemeeting.com
10 DNS response 204.176.46.177
11 HTTPS between client and www0.livemeeting.com
12 Certificate/key presented and verified
13 redirect to www112.livemeeting.com – Livemeeting Portal Server
14 DNS query for www112.livemeeting.com
15 DNS response 64.41.193.32
16 HTTPS negotiation between client and www112.livemeeting.com
17 Certificate/key presented and verified
18 DNS lookup for fwd112.livemeeting.com
19 DNS reply 64.41.193.46 – Web Conferencing Server
20 HTTPS negotiation between client and fwd112.livemeeting.com
21 DNS query for apx113.livemeeting.com
22 DNS response 64.41.193.20 – Access Edge Server
23 HTTPS negotiation between client and apx113.livemeeting.com
24 TCP / HTTPS connection from client to 216.34.51.34 – A/V Edge Server (note: no DNS lookup)
25 STUN request from client to 216.34.51.34 on UDP port 3478 – (Voice and Video Traffic)
26 STUN / UDP traffic from client to 216.34.51.34 on UDP port 3478 – (Voice and Video Traffic)
The official word on what ports get used looks something like this (although I haven’t seen a client connect on port 8057 yet):
|
Source Port (client) |
Destination Port (server) |
Network/ApplicationProtocol |
|
1024 – 65535 |
TCP 443 |
Media session control;TCP / SIP / TLS |
|
1024-65535 |
TCP 8057 |
LM Client connection / authentication (if available); TCP |
|
1024 – 65535 |
UDP 3478 |
Media to A/V Edge Server; UDP / STUN / TURN |
|
1024 – 65535 |
TCP 443 |
Media failback (if 3478 is not open); TCP / STUN / TURN |
Also, if users wish to view the recordings via streaming media (i.e. not needing to download the entire recording in order to view it), several other ports will need to be opened on the firewall including:
- TCP ports 80, 443, 554, 1755, 7070
- UDP ports 1755 and 5055
Lastly, it was pretty tricky to find out which exact servers and subnets the LiveMeeting client was going to connect to. My best advice here is to get the list from the MS account team who is helping you provision the LiveMeeting service.
