Shared LAN emulation method and apparatus having VLAN recognition and LLID management functions on EPON

• US 20050083950A1
• Filed: 06/14/2004
• Published: 04/21/2005
• Est. Priority Date: 10/21/2003
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Kim, Tae Il, Lee, Hyeong Ho, Choi, Su Il
• Granted Patent: US 7,613,187 B2
• Time in Patent Office: Days
• US Class Current: 370/395.530
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 11/0071 Provisions for the electrical-optical layer interface
• CPC Class Codes: H04Q 2011/0077 Labelling aspects, e.g. multiprotocol label switching [MPLS], G-MPLS, MPAS

Abstract

Disclosed herein is a shared Local Area Network (LAN) emulation method and apparatus. The method includes the following four steps. At the first step, a Logical Link Identifier (LLID) management table is set up to assign unique LLIDs to a plurality of Optical Network Units (ONUs) and manage the assigned LLIDs so as to identify the plurality of ONUs connected to a single Optical Line Terminal (OLT). Thereafter, a MAC address table is set up for the LLIDs to learn MAC addresses of the ONUs. Thereafter, the unique LLIDs are assigned to ONUs when the ONUs request registration from the OLT. Finally, data frames, which are received by a Shared LAN Emulation (SLE) layer of the OLT, are bridged using the LLIDs, VIDs of Virtual LANs to which the ONUs belong and destination MAC addresses of the data frames so as to provide a single matched port between a Logical Link Control (LLC) layer and a MAC layer of the OLT.

Claims

1. A shared Local Area Network (LAN) emulation method, comprising the steps of:

setting up a Logical Link Identifier (LLID) management table for assigning unique LLIDs to a plurality of Optical Network Units (ONUs) and managing the assigned LLIDs so as to identify the plurality of ONUs connected to a single Optical Line Terminal (OLT);

setting up a MAC address table for the LLIDs learning MAC addresses of the ONUs;

assigning the unique LLIDs to ONUs when the ONUs request registration from the OLT; and

bridging data frames, which are received by a Shared LAN Emulation (SLE) layer of the OLT, using the LLIDs, VIDs of Virtual LANs to which the ONUs belong and destination MAC addresses of the data frames so as to provide a single matched port between a Logical Link Control (LLC) layer and a MAC layer of the OLT.

2. The shared LAN emulation method as set forth in claim 1, wherein the LLID management table includes:

LLIDs for identifying the ONUs;

ONU MAC addresses corresponding to the MAC addresses of the ONUs having requested connection from the OLT;

VIDs for identifying virtual LANs of groups of ONUs to which the ONUs belong;

authentication information fields for determining whether connection of the ONUs is allowed;

connection setup information fields for determining whether the ONUs have been connected to the OLT and links have been set up therebetween; and

subscriber MAC table pointer fields for the respective LLIDs, the subscriber MAC table pointer fields corresponding to pointer values of the MAC table, the MAC table being set up by learning the MAC addresses for the respective LLIDs.

3. The shared LAN emulation method as set forth in claim 1, wherein the MAC address table includes LLIDs, MAC addresses and VIDs.

4. The shared LAN emulation method as set forth in claim 1, wherein the step of assigning LLIDs comprises the steps of:

if the ONUs having requested registration have been already registered and LLIDs having been already assigned to the ONUs exist, assigning the LLIDs having been already assigned to the ONUs having requested registration;

if the ONUs having requested registration have been already registered but the LLIDs having been already assigned to the ONUs do not exist, assigning available LLIDs to the ONUs having requested registration; and

if the ONUs having requested registration have been already registered but the LLIDs having been already assigned to the ONUs and the available LLIDs do not exist, assigning new dynamic LLIDs or LLIDs appointed by an operator to the ONUs having requested registration.

5. The shared LAN emulation method as set forth in claim 1, wherein the step of bridging the data frames comprises the steps of:

if each of the received data frames entering the SLE layer corresponds to a broadcast frame and have a VID, transmitting the received data frame to only an ONU group having a VID identical with the VID of the data frame;

if the received frame corresponds to the broadcast frame entering the SLE layer from a layer higher than the SLE layer but do not have a VID, transmitting the data frame so that all the ONUs can receive packets;

if the received frame corresponds to the broadcast frame entering the SLE layer from a layer lower than the SLE layer but do not have a VID, transmitting the data frame so that only an ONU having a source LLID cannot receive a packet;

if the received frame has the VID of the destination LLID and but VID of the received frame is different from the VID of the destination LLID, discarding the received unicast frame; and

if the received frame has the VID of the destination LLID and the VID of the received frame is identical with the VID of the destination LLID, setting the LLID of the frame to the destination LLID and transmitting the unicast frame.

6. A shared LAN emulation apparatus, comprising:

means for storing a LLID management table for assigning unique LLIDs to a plurality of ONUs and managing the assigned LLIDs so as to identify the plurality of ONUs connected to a single OLT;

means for storing a MAC address table for the LLIDs learning MAC addresses of the ONUs;

a LLID management unit for assigning the unique LLIDs to ONUs and managing the assigned LLIDs when the ONUs request registration from the OLT; and

a bridging unit for bridging data frames, which are received by a SLE layer of the OLT, using the LLIDs, VIDs of Virtual LANs to which the ONUs belong and destination MAC addresses of the data frames so as to provide a single matched port between a LLC layer and a MAC layer of the OLT.

7. The shared LAN emulation apparatus as set forth in claim 6, wherein the LLID management table includes:

LLIDs for identifying the ONUs;

ONU MAC addresses corresponding to the MAC addresses of the ONUs having requested connection from the OLT;

VIDs for identifying virtual LANs of groups of ONUs to which the ONUs belong;

authentication information fields for determining whether connection of the ONUs is allowed;

connection setup information fields for determining whether the ONUs have been connected to the OLT and links have been set up therebetween; and

subscriber MAC table pointer fields for the respective LLIDs, the subscriber MAC table pointer fields corresponding to pointer values of the MAC table, the MAC table being set up by learning the MAC addresses for the respective LLIDs.

8. The shared LAN emulation apparatus as set forth in claim 6, wherein the MAC address table includes LLIDs, MAC addresses and VIDs.

9. The shared LAN emulation apparatus as set forth in claim 6, wherein the LLIDs management unit comprises:

means for, if the ONUs having requested registration have been already registered and LLIDs having been already assigned to the ONUs exist, assigning the LLIDs having been already assigned to the ONUs having requested registration;

means for, if the ONUs having requested registration have been already registered but the LLIDs having been already assigned to the ONUs do not exist, assigning available LLIDs to the ONUs having requested registration; and

means for, if the ONUs having requested registration have been already registered but the LLIDs having been already assigned to the ONUs and the available LLIDs do not exist, assigning new dynamic LLIDs or LLIDs appointed by an operator to the ONUs having requested registration.

10. The shared LAN emulation apparatus as set forth in claim 6, wherein the bridging unit comprises:

means for, if each of the received data frames entering the SLE layer corresponds to a broadcast frame and have a VID, transmitting the received data frame to only an ONU group having a VID identical with the VID of the data frame;

means for, if the received frame corresponds to the broadcast frame entering the SLE layer from a layer higher than the SLE layer but do not have a VID, transmitting the data frame so that all the ONUs can receive packets;

means for, if the received frame corresponds to the broadcast frame entering the SLE layer from a layer lower than the SLE layer but do not have a VID, transmitting the data frame so that only an ONU having a source LLID cannot receive a packet;

means for, if the received frame has the VID of the destination LLID and but VID of the received frame is different from the VID of the destination LLID, discarding the received unicast frame; and

means for, if the received frame has the VID of the destination LLID and the VID of the received frame is identical with the VID of the destination LLID, setting the LLID of the frame to the destination LLID and transmitting the unicast frame.

11. A computer-readable storage medium having stored therein a program that executes the steps of:

setting up a LLID management table for assigning unique LLIDs to a plurality of ONUs and managing the assigned LLIDs so as to identify the plurality of ONUs connected to a single OLT;

setting up a MAC address table for the LLIDs learning MAC addresses of the ONUs;

assigning the unique LLIDs to ONUs when the ONUs request registration from the OLT; and

bridging data frames, which are received by an SLE layer of the OLT, using the LLIDs, VIDs of Virtual LANs to which the ONUs belong and destination MAC addresses of the data frames so as to provide a single matched port between a LLC layer and a MAC layer of the OLT.