User manual

C HAPTER 4 | Configuring the Switch
Managing VoIP Traffic
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◆ IP Address – The IP address for a subnet. Valid IP addresses consist of
four decimal numbers, 0 to 255, separated by periods.
◆ Mask Length – The network mask length.
◆ VLAN ID – VLAN to which matching IP subnet traffic is forwarded.
(Range: 1-4095)
◆ Port Members – Ports assigned to an IP subnet VLAN.
WEB INTERFACE
To configure an IP Subnet-based VLAN:
1. Click Advanced Configuration, VCL, IP Subnet-based VLAN.
2. Enter the VCE identifier, the network mask length, and the VLAN
identifier. Then mark the ports which will be assigned to this VLAN.
3. Click Save.
Figure 72: Assigning Ports to an IP Subnet-based VLAN
MANAGING VOIP TRAFFIC
When IP telephony is deployed in an enterprise network, it is
recommended to isolate the Voice over IP (VoIP) network traffic from other
data traffic. Traffic isolation can provide higher voice quality by preventing
excessive packet delays, packet loss, and jitter. This is best achieved by
assigning all VoIP traffic to a single Voice VLAN.
The use of a Voice VLAN has several advantages. It provides security by
isolating the VoIP traffic from other data traffic. End-to-end QoS policies
and high priority can be applied to VoIP VLAN traffic across the network,
guaranteeing the bandwidth it needs. VLAN isolation also protects against
disruptive broadcast and multicast traffic that can seriously affect voice
quality.
The switch allows you to specify a Voice VLAN for the network and set a
service priority for the VoIP traffic. VoIP traffic can be detected on switch
ports by using the source MAC address of packets, or by using LLDP (IEEE
802.1ab) to discover connected VoIP devices. When VoIP traffic is detected
on a configured port, the switch automatically assigns the port as a tagged
member the Voice VLAN. Alternatively, switch ports can be manually
configured.