3com 5000 ATM User Manual
2-10
C
HAPTER
2: LAN E
MULATION
O
VERVIEW
LECS Connection
The LEC must determine the ATM address of its LECS and establish a
connection to the LECS. The LEC attempts each of the following
methods, in the order provided, to connect to its LECS:
connection to the LECS. The LEC attempts each of the following
methods, in the order provided, to connect to its LECS:
1 Uses a locally configured LECS ATM address.
2 Queries the ILMI Service Registry MIB of the attached ATM switch for
one or more LECS ATM addresses.
3 Uses a predefined “well-known” LECS ATM address.
The use of another LANE 1.0 method of LECS connection, a PVC
(Permanent Virtual Circuit) connection over VPI/VCI 0/17 (Virtual Path
Identifier/Virtual Circuit Identifier), is not supported by the ATM
Backbone SwitchModule.
(Permanent Virtual Circuit) connection over VPI/VCI 0/17 (Virtual Path
Identifier/Virtual Circuit Identifier), is not supported by the ATM
Backbone SwitchModule.
The LEC proceeds to the Configuration stage when it establishes a
connection to the LECS.
connection to the LECS.
Configuration
During the configuration stage, the LEC:
1 Sends a Configuration Request, containing identifying information
about itself, to the LECS.
2 Receives a Configuration Response from the LECS containing the ATM
address of the LES to which the LEC is assigned, as well as emulated
LAN parameters such as ELAN type, frame size, and ELAN name.
LAN parameters such as ELAN type, frame size, and ELAN name.
Joining
During the Joining stage, the LEC:
1 Connects to the LES and sends a Join Request containing LANE
parameter settings that were locally configured (manual mode) or
obtained from the LECS (automatic mode).
obtained from the LECS (automatic mode).
2 Receives a Join Response from the LES indicating whether the LEC is
accepted onto the emulated LAN controlled by that LES.