Below are the three login processes which are responsible
for the creation and maintenance of communication link between initiator and
target.
for the creation and maintenance of communication link between initiator and
target.
1. Fabric Login:- It is
known as FLOGI. It establishes the session between N-port and F-port. It is mandatory
process for point-to-point and Fabric topology, without it N_port will not able
to send or receive data. It is optional for Arbitrated loop. It performs below
function so that N_port can register to the fabric.
known as FLOGI. It establishes the session between N-port and F-port. It is mandatory
process for point-to-point and Fabric topology, without it N_port will not able
to send or receive data. It is optional for Arbitrated loop. It performs below
function so that N_port can register to the fabric.
- As soon as N_port is connected to F_port, it
will register itself in the fabric by sending the fabric login request. In
return F_port will assign a 24-bit FCID to the N-port. - N_port also negotiate the link flow control
parameter i.e. Buffer-to-Buffer credit with F_port. - If N_port and F_port supports authentication
then they are negotiate the authentication parameters during FLOGI.
N_port sends the Flogi frame (containing WWNN, WWPN and B2B credit) to a well-known address of 0xFFFFFE. In return switch will send the accept frame (ACC).
2. N-Port Login:- It is also known as PLOGI.
It creates a FC4 session between the end devices. It is responsible to create and maintain the
session between two N-Port. During PLOGI, N_port will negotiate the end-to-end
credit. PLOGI also enables N_port to learn other characteristics like WWNN,
WWPN etc. of other end N_port.
It creates a FC4 session between the end devices. It is responsible to create and maintain the
session between two N-Port. During PLOGI, N_port will negotiate the end-to-end
credit. PLOGI also enables N_port to learn other characteristics like WWNN,
WWPN etc. of other end N_port.
N_port sends the PLOGI on a well-known address of 0xFFFFFC.
3. Process Login:- Also known as PRLI. It creates and
maintains a session between two FC4 processes that are connected via two
different N_port between initiator and target.
maintains a session between two FC4 processes that are connected via two
different N_port between initiator and target.