Router apparatus and frame transfer method

(54) ROUTER APPARATUS AND FRAME TRANSFER METHOD

(75) Inventor: Shigeo Matsuzawa, Tokyo (JP)

(73) Assignee: Kabushiki Kaisha Toshiba, Kawasaki (JP)

( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 212 days.

This patent is subject to a terminal disclaimer.

(21) Appl. No.: 10/270,192

(22) Filed: Oct. 15, 2002

(65) Prior Publication Data

US 2003/0067929 Al Apr. 10, 2003

Related U.S. Application Data

(63) Continuation of application No. 09/267,769, filed on Mar. 15, 1999, now Pat. No. 6,490,292.

(30) Foreign Application Priority Data

Mar. 13, 1998 (JP) 10-062890

(51) Int. CI.7 H04L 12/56

(52) U.S. CI 370/401; 370/395.1

(58) Field of Search 370/465, 464,

370/466, 467, 468, 474, 389, 399, 229, 231, 232, 233, 401, 402, 403, 351, 352, 470, 471, 475, 396, 397, 395.31, 395.52, 395.53, 395.1

(56) References Cited

U.S. PATENT DOCUMENTS 5,835,710 A 11/1998 Nagami et al.

A router has a lunction ol providing a label used for translerring a datalink frame by a cut-through operation (i.e., datalink-layer switching). Whether the cut-through operation is to be performed or not is indicated by a cut-through declarator described in a prescribed portion (e.g., OUI field) within an upper-layer-protocol identilying information region (e.g., SNAP field) ol a received frame or signaling message. The information described in the remaining portion (e.g., PID field) within the upper-layer-protocol identilying information region and the information described in the destination or source datalink-layer address region ol the received frame or signaling message are used as the label for identilying in the datalink layer a packet flow to which a received frame belongs.

9 Claims, 13 Drawing Sheets