3com nj200 Manual Suplementar

3 C O M

®

N J 2 0 0   N E T W O R K   J A C K — V L A N S   &   T R A F F I C   P R I O R I T I Z AT I O N

For most outbound data traffic, the PAN ports add VID tags to the Ethernet frames prior
to them reaching the LAN (uplink) port. In this case, the LAN port simply delivers the
outbound traffic to the network. Once on the network, the VID-tagged traffic can be
forwarded and segmented by any 802.1Q enabled switch port.

For broadcast, multicast, and unicast traffic, the outgoing Ethernet frames are tagged at
the LAN port. This tagged traffic is subsequently identified and forwarded by 802.1Q-
enabled upstream network switches. 

For a step-by-step guide on setting up outbound traffic tags for the LAN port, please
refer to the section titled, Setting the Outgoing Tag Scheme.

3

VLAN Configuration 
and Setup

Although the NJ200 switch does not use VLAN tags, these tags are needed by many
other network devices—such as upstream switches or a VoIP phone connected to a PAN
port. To ensure traffic is appropriately tagged as it enters and exits, the NJ200 Network
Jack can be configured to add tags, remove tags, or leave frames unmodified. 

The ingress mode uses the receiving port buffer to inspect and process inbound traffic.
The egress mode uses the transmitting port buffer to inspect and process outbound traf-
fic. The four settings are summarized in Table 2.

Table 2. Ingress and Egress Control Settings

Tagged

Tagged

Frames received unmodified

Frames transmitted unmodified

Tagged

Untagged

Remove 802.1 tag if present

Frames transmitted unmodified

Untagged

Untagged

Frames received unmodified

Frames transmitted unmodified

Untagged

Tagged

Frames received unmodified

Add 802.1 tag to untagged frame