Fibre Channel Addressing and Routing Fibre Channel Addressing
Addressing FC Frames
The 24 bit Destination ID (D_ID) and Source ID (S_ID) are contained in the FC Frame Header and used for routing the frame to it’s destination port
SOF
4
Header
24
bits 31
Word
0 1 2 3 4 5
R_CTL
CS_CTL TYPE
SEQ_ID OX_ID Parameter DF-CTL
Payload
0 - 2112
CRC EOF
4 4 Bytes
24 23
16 15
D_ID S_ID
F_CTL
SEQ_CNT RX_ID
8 7
0
This slide shows where the Fibre Channel address is used in the frame header: • The Destination ID (D-ID) is located in the first word of the header so that the frame can be routed across the switch before the rest of the frame has even been received by the switch.
• The Source ID (S_ID) shows where the frame has come from. • These fields are always 24 bits long in all topologies. • Frame headers were covered in more detail in a previous module.