3com WXR100 3CRWXR10095A User Manual

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Enabling Prioritization for Legacy Voice over IP
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Configuring a VLAN for Voice Clients
MSS requires all clients to be authenticated by RADIUS or the local 
database, and to be authorized for a specific VLAN. MSS places the user 
in the authorized VLAN. 
„
Configure a VLAN for voice clients
You can use the same VLAN for other clients. However, it is a best 
practice to use the VLAN primarily, if not exclusively, for voice traffic.
„
Disable IGMP snooping in the VLAN. (Disabling this feature is required 
for SVP.) 
To configure a VLAN and a last-resort user for the voice SSID:
WX4400# set vlan 2 name v1 port 3
WX4400# set igmp disable vlan v1
The set vlan and set igmp commands create VLAN v1 and add the 
uplink port to it, then disable IGMP snooping in the VLAN. 
Configuring an ACL to Prioritize Voice Traffic
MSS does not provide priority forwarding for SVP traffic by default. To 
enable prioritization for SVP traffic, you must configure an ACL and map 
it to the both the inbound and outbound directions of the VLAN to which 
the voice clients are assigned. The ACL must contain an ACE that 
matches on IP protocol 119 and marks the IP ToS bits in matching packets 
with CoS value 7. When a MAP receives a packet with CoS value 7, the 
MAP places the packet in the voice queue for priority forwarding. 
If the VLAN will be shared by other clients, you also need to add an ACE 
that permits the traffic that is not using IP protocol 119. Otherwise, the 
WX drops this traffic. Every ACL has an implicit ACE at the end that 
denies all traffic that does not match any of the other ACEs in the ACL.
After you configure the ACE and map it to the VLAN, you must commit 
the VLAN to the configuration. The ACL does not take effect until you 
map it and commit it.
The following commands configure an ACE to prioritize SVP traffic and 
map the ACE to the outbound direction of the voice VLAN:
WX1200# set security acl ip SVP permit cos 7 udp 10.2.4.69 
255.255.255.255 gt 0 any gt 0