
AOS-W Instant 6.3.1.1-4.0 | User Guide Extended Voice and Video | 301
Chapter 29
Extended Voice and Video
AOS-W Instant has the added ability to identify and prioritize voice and video traffic from applications such as
Microsoft Office Communications Server (OCS) and Apple Facetime.
QoS for Microsoft Office OCS and Apple Facetime
Voice and video devices use a signaling protocol to establish, control, and terminate voice and video calls. These
control or signaling sessions are usually permitted using pre-defined ACLs. If the control signaling packets are
encrypted, the OAW-IAP cannot determine the dynamic ports are used for voice or video traffic. In these cases, the
OAW-IAP has to use an ACL with the classify-media option enabled to identify the voice or video flow based on a
deep packet inspection and analysis of the actual traffic.
Microsoft OCS
Microsoft Office Communications Server (OCS) uses Session Initiation Protocol (SIP) over TLS to establish,
control, and terminate voice and video calls.
Apple Facetime
When an Apple device starts a Facetime video call, it initiates a TCP session to the Apple Facetime server over port
5223, then sends SIP signaling messages over a non-default port. When media traffic starts flowing, audio and video
data are sent through that same port using RTP. (The audio and video packets are interleaved in the air, though
individual the sessions can be uniquely identified using their payload type and sequence numbers.) The RTP header
and payload also get encapsulated under the TURN ChannelData Messages. The Facetime call is terminated with a
SIP BYE message that can be sent by either party.
The following table lists the ports used by Apple Facetime. Facetime users need to be assigned a role where traffic is
allowed on these ports.
Port Packet Type
53 TCP/UDP
443 TCP
3478-3497 UDP
5223 TCP
16384-16387 UDP
16393-16402 UDP
Table 59:
Ports Used by the Apple Facetime Application
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