Frame transfer method and node in Ethernet

• US 7,783,705 B2
• Filed: 08/18/2003
• Issued: 08/24/2010
• Est. Priority Date: 08/22/2002
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Iwata, Atsushi, Hidaka, Youichi, Shibutani, Makoto, Enomoto, Nobuyuki, Umayabashi, Masaki
• Primary Examiner(s): Walsh; John B.
• Application Number:
  US10/642,197
• Publication Number:
  US 20040039832A1
• Time in Patent Office: 2,563 Days
• Field of Search: 709/206, 709/230
• US Class Current: 709/206
• CPC Class Codes: H04L 12/4666 Operational details on the addition or the stripping of a tag in a frame, e.g. at a provider edge node
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames

Abstract

A node to relay the Ethernet frame provided with means to insert, in the relay process of the frame, two or more VLAN tags into the frame at a time and to remove the inserted VLAN tags wherein a TTL area to show the frame survival time is provided in the VLAN tag to be inserted to the frame so that whether the survival time has been elapsed or not is checked by the value in the TTL area and the frame after elapse of the survival time is discarded without being relayed.

Claims

1. A node in an Ethernet network to relay a modified Ethernet frame, comprising:

an element which inserts two or more VLAN tags into said frame and removes an other VLAN tag in a relay process of said frame,

wherein said frame comprises an Ethernet frame, as modified such that network control information is selectively stored to said VLAN tags and said network control information is not restricted to a 64-byte minimum frame size restriction of network control information, as defined by a standard of said Ethernet.

2. A node as set forth in claim 1, further comprising:

an element which replaces two or more VLAN tags of said frame at a time.

3. A node as set forth in claim 1, further comprising:

an element which administrates said two or more VLAN tags using a forwarding table memory for a change of frame contents during a frame relay.

4. A node as set forth in claim 1, further comprising:

an element which searches a forwarding table memory using an information from two or more VLAN tags in said frame during a frame relay.

5. A node as set forth in claim 1, further comprising:

an element which searches a forwarding table memory in a relay process of said frame with a combination of an information from two or more VLAN tags in said frame and an input port, a destination MAC address, a source MAC address and a TYPE field information.

6. A node as set forth in claim 1, further comprising an element which:

provides a TTL area to show a survival time of a frame in said VLAN tag inserted to said frame;

checks whether said survival time has elapsed or not by a value in said TTL area; and

discards said frame after elapse of said survival time without relaying said frame in a relay process of said frame.

7. A node as set forth in claim 6, further comprising:

an element which decrements the value in said TTL area by one every time said frame is relayed.

8. The node of claim 1, wherein said network control information comprises 32-bit network control tags.

9. A node as set forth in claim 1, further comprising:

an element which changes a self-node status administration corresponding to a content of said VLAN tag.

10. A node as set forth in claim 1, wherein

a node status is stored to an area of said VLAN tag in the relayed frame corresponding to a self-node status.

11. A frame transfer method of a node in an Ethernet network to relay a modified Ethernet frame, said method comprising:

receiving said frame in said node, said frame comprising an Ethernet frame as modified such that network control information can selectively be stored to a VLAN tag, said network control information not being restricted to a 64-byte minimum frame size restriction of network control information, as defined by a standard of said Ethernet;

inserting two or more VLAN tags into said frame and removing at least one other VLAN tag from said frame in a relay process of said frame; and

forwarding said frame.

12. A frame transfer method as set forth in claim 11, wherein

a forwarding table memory for frame contents change during a frame relay is used for administration of said two or more VLAN tags.

13. A frame transfer method as set forth in claim 11, wherein

a forwarding table memory is searched during a frame relay using an information from two or more VLAN tags in said frame.

14. A frame transfer method as set forth in claim 11, wherein

a forwarding table memory is searched in a relay process of said frame with a combination of an information from two or more VLAN tags in said frame and an input port, a destination MAC address, a source MAC address and a TYPE field information.

15. A frame transfer method as set forth in claim 11, wherein:

a TTL area to show a survival time of the frame is provided in said VLAN tag that is inserted to said frame;

whether said survival time has been elapsed or not is checked by a value in said TTL area; and

said frame after elapse of said survival time is discarded without being relayed in the relay process of said frame.

16. A frame transfer method as set forth in claim 15, wherein the value in said TTL area is decremented by one every time said frame is relayed.

17. A frame transfer method as set forth in claim 11, wherein

a node status is stored to said VLAN tag area in the relayed frame corresponding to a self-node status.

18. A frame transfer method as set forth in claim 11, further comprising:

changing a self-node status administration corresponding to contents of said VLAN tag.