Video from alternate IP - how to confirm it?
Posted: Wed Mar 07, 2012 9:05 pm
When an H.323 call sets up between two endpoints A, B, they exchange channel information
and A stats sending video to B at the address and port that B specified (in the HG.245 openLogicalChannelAck message, for example).
What if B wants to validate that the video is really coming from A? That is, B knows what
address it is in conference with. Let's say A is 100.100.100.100. But it sends its
video to me from 100.100.100.101. Some systems (most notably
recent-generation MCUs like the Polycom RMX or the ZTE systems) will send their video
from a second IP address, not the one that set up the call.
Suppose I am station B, and I see video coming at me from this other IP, and I want to make
sure it's not some rogue sending me improper video? Is there something in the H.245 message exchange that should have told me to expect the video to come from this other IP address? Is there a standard
for handling this, or allowing it? Or am I suppose to just ignore the sender's address and play
whatever video shows up on my port?
and A stats sending video to B at the address and port that B specified (in the HG.245 openLogicalChannelAck message, for example).
What if B wants to validate that the video is really coming from A? That is, B knows what
address it is in conference with. Let's say A is 100.100.100.100. But it sends its
video to me from 100.100.100.101. Some systems (most notably
recent-generation MCUs like the Polycom RMX or the ZTE systems) will send their video
from a second IP address, not the one that set up the call.
Suppose I am station B, and I see video coming at me from this other IP, and I want to make
sure it's not some rogue sending me improper video? Is there something in the H.245 message exchange that should have told me to expect the video to come from this other IP address? Is there a standard
for handling this, or allowing it? Or am I suppose to just ignore the sender's address and play
whatever video shows up on my port?