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3 C O M

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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

Forwarding Outbound-Traffic to the LAN

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

Setting the Ingress and Egress Modes

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

Inbound

Outbound 

Ingress Mode 

Egress Mode

Traffic

Traffic

Setting

Setting

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

Summary of Contents for IntelliJack NJ200

Page 1: ...TECHNICAL BRIEF 3Com NJ200 Network Jack Management Feature Virtual LANs and Traffic Prioritization...

Page 2: ...nd traffic to include VLAN tags Forward VLAN tagged traffic This supports other devices that rely on Ethernet frame tags to correctly recognize and forward VLAN traffic The section titled Setting the...

Page 3: ...g the Ingress and Egress Modes 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...

Page 4: ...g Set 802 1 VLAN Tag Set Egress rule set to add tag Ingress rule set to remove tag Do not modify tag information Forward frame to PAN port Forward frame to PAN port Add VLAN tag information Remove all...

Page 5: ...n window Setting the PAN Port Associations The PAN device ports can support up to four different VLAN domains 3Com Central Configuration Manager lets you assign individual ports to four separate VLANs...

Page 6: ...r but not ports 1 or 2 Note It is possible to override these port configurations with a higher level device such as a core switch that supports Layer 3 IP forwarding between VLANs Setting Outgoing and...

Page 7: ...field PAN ports 1 and 2 are now configured as part of the VLAN 1 subnet 4 Repeat the last two steps to configure PAN ports 3 and 4 as part of the VLAN 2 subnet Click OK to exit configuration window 5...

Page 8: ...lications are used by accounting departments to handle AR AP taxes interest payments and other business critical processes These powerful programs need immediate and reliable access to large datasets...

Page 9: ...or 3 2 4 or 5 4 6 or 7 6 Traffic Prioritization Configuration and Setup YES YES NO NO NO NO YES YES Inspect Ethernet frame Inspect Ethernet frame 802 1 Priority Tag Set 802 1 Priority Tag Set Egress...

Page 10: ...ollowing settings a None b 802 1p Traffic Class fields c Use IP TOS Diffserv fields d Both To ignore the priority tags on incoming Ethernet frames set the Priority Look up Scheme to None Note Priority...

Page 11: ...3 Click on the Hardware Settings tab to view and configure the Priority Schedule Policy settings You should see a window like this 4 Under Priority Schedule Policy choose one of the following a 8 4 2...

Page 12: ...icular a telephone conference with a trans Pacific client suffered in quality and usability The meeting ended up being postponed until the next day a 24 hour delay that cost the company many thousands...

Page 13: ...ssion Not allowed Port Setting Default Value State Forwarding Link Autonegotiation Flow Control Off MDI X Force MDI Multicast Limit 3 Priority Lookup Tag and IPV4 Port Priority 1 VLAN ID 1 Port based...

Page 14: ...accept liability for any errors or mistakes which may arise Specifications and other informa tion in this document may be subject to change without notice NJ_VirtualLANs 09 03 3Com NJ200 Network Jack...

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