NEC Sl2100 Networking Manual page 113

ISSUE 1.0
13.5 VLANs
A VLAN is used to logically break up the network and minimize broadcast domains. Without VLANS,
the network must be physically segmented to break up broadcast domains. Each network segment is
then connected through a routing device adding latency and cost. Latency is a delay in the
transmission of data and is caused by routing packets from one LAN to another. In a VoIP
environment latency must be kept to a minimum.
802.1Q allows a change in the Ethernet Type value in the Ethernet header tagging the Protocol ID
0x8100, identifying this frame as an 802.1Q frame. This inserts additional bytes into the frame that
composes the VLAN ID (valid IDs = 1 ~ 4094).
802.1P allows you to prioritize the VLAN using a 3-bit priority field in the 802.1Q header. Valid VLAN
priority assignments are 0 ~7. A tag of 0 is treated as normal data traffic giving no priority. Under
normal circumstances the higher the tag numbers, the higher the priority. However this is left up to the
network administrator as they could set the exact opposite where the lower tag numbers have a higher
priority.
Tagging Voice and Data Packets
Built into the IP phones is a 2 port 10/100 manageable data switch allowing for a PC connection on
the back of the IP phone. This built in data switch also supports 802.1Q and 802.1P VLAN tagging
capabilities.
The following procedures describe two methods for tagging the voice packets and the data packets
separately, using the PC, or using the phone keypad.
13.5.1 Logging In on the PC
1. Web browse to the IP address of phone.
2. To log in, enter default user name: ADMIN
3. Enter default password: 6633222
Networking Manual
SL2100
9-15