VLAN DATA FRAMING AND TRANSMISSION

• US 20110058559A1
• Filed: 08/07/2008
• Published: 03/10/2011
• Est. Priority Date: 08/08/2007
• Status: Abandoned Application

• Current Assignee: Packetfront Network Products AB (ShortCap AB)
• Original Assignee: Packetfront Systems AB (Tosca IOM Ltd.)
• Inventors: Oman, Andreas
• Application Number:
  US12/672,469
• Publication Number:
  US 20110058559A1
• Time in Patent Office: Days
• US Class Current: 370/395.53
• CPC Class Codes: H04L 12/4645 Details on frame tagging routing of packets H04L45/00; support for virtual LAN H04L49/354

Abstract

Amethod of framing data for transmission to or from one of a number of users connected to a VLAN data network, comprising dividing the data into frames including a header and a payload, the header comprising a portion of one of two selectable values assigned according to whether the data is to be transmitted from or to a user, wherein the header comprises a VLAN tag including a Tag Protocol ID (TPID) portion and a Tag Control Information (TCI) portion, a first TPID value being assigned to data to be transmitted from the user and a second, different, TPID value being assigned to data to be transmitted to a user.

Claims

1. A method of framing data for transmission to or from one of a number of users connected to a VLAN data network, comprising:

sending data from a first user to a first layer 2 switch;

dividing the data in the first layer 2 switch into frames including a header and a payload, the header comprising a portion of one of two selectable values assigned according to whether the data is to be transmitted from or to a user, wherein the header comprises a VLAN tag including a Tag Protocol ID (TPID) portion and a Tag Control Information (TCI) portion, a first TPID value being assigned in the first layer 2 switch to be indicative of data being transmitted from the user;

forwarding the framed data from the first layer 2 switch to a distribution router comprising the VLAN;

reframing the data in the distribution router so as to assign a second, different, TPID value which is indicative of data being transmitted to a second user;

forwarding the re-framed data from the distribution router to a second layer 2 switch to which the second user is connected; and

transmitting the data from the second layer 2 switch to the second user.

2. A method as claimed in claim 1, wherein the TCI portion includes a VLAN ID field specifying the VLAN to which the frame belongs.

3. A method as claimed in claim 1 or 2, comprising assigning the same VLAN ID to frames for transmission to or from the same user in a specific VLAN.

4. A method as claimed in any preceding claim, comprising assigning the first EtherType value for data transmitted from a user at a layer 2 switch to which the user is connected.

5. A method as claimed in any preceding claim comprising assigning the second EtherType value for data transmitted to a user at a distribution router forming part of the network to which the user is connected.

6. A method as claimed in claim 1, wherein the first and second users are connected to the same layer 2 switch or to different layer 2 switches.