ASCOM Ascotel AIP 6350, System Manual

Page: 42 / 64

AIP 6350 / Office 35IP
42 Network Environment
6.2 Prioritising
If the IP network is to guarantee the bandwidth required for call connections,
voice packets have to be given priority compared with other data packets.
The system supports the following prioritisation methods:
• Expanded IP frames as per IEEE 802.1p/Q (CoS, Layer 2):
AIP and IP terminals use the prioritisation field in the expanded frame header
to specify the priority. Prioritisation is effected in the switches. All the switches
used must therefore support prioritisation as per IEEE 802.1p/Q and be config-
ured accordingly for the method to be supported effectively.
• Type of Service (ToS, Layer 3):
AIP and IP terminals use the ToS field (8 priority levels) of the IP header to spec-
ify the priority (tagging). Prioritisation is effected in the routers or in the Layer
3 switches. The routers used must therefore support ToS prioritisation and be
configured accordingly. The router handles non-prioritised data packets with
standard priority.
Both prioritisation methods can be used simultaneously.
Tab. 17: Prioritisation settings based on the example of the reference model
The settings are effective for both the AIP and the IP terminals (see also page 49,
Tab. 28 ).
Parameters Parameter value
1)
1)
Here they all correspond to the initialisation values
CoS Priorisation Off
CoS Priorisation Level 5 Interactive Media
ToS Priorisation Level 5 CRITIC_ECP
ToS Service Type 8 Low Latency