L-ET4148-50C-DB LSI, L-ET4148-50C-DB Datasheet - Page 282

• Manufacturer Part Number: L-ET4148-50C-DB
• Manufacturer: LSI

Specifications of L-ET4148-50C-DB

• Lead Free Status / RoHS Status: Supplier Unconfirmed

ET4148-50
Single-Chip 48 x 1 Gbit/s + 2 x 10 Gbits/s Layer 2+ Ethernet Switch
Appendix B: Configuration
Access Control Lists
Index Tables
A series of tables are used to establish indirections from one stage of ACL processing to the next. These indirec-
tions minimize redundancy and provide the opportunity for the sharing of table entries from one ACE to the next.
The following figure shows how the various index tables are incorporated into the look-up process.
VLAN Index Table. When the port-based VLAN mode is selected via Acl_Mode, there is a simple one-to-one asso-
ciation between a receive port and its associated ACL. Essentially, the port number and the ACL number are the
same.
When the ACL function is configured to be VLAN-based, Acl_Vlan_Index_Table is used to establish the mapping
between a VLAN index and an ACL. This register is a 256-entry table that is addressed by the receive packet’s 8-
bit VLAN index. Returned from this table is a 6-bit value (acl_index[5:0]) that is used to select an individual
ACL.
Note: There is an important distinction between a VLAN identifier and a VLAN index. A VLAN identifier is the 12-bit
The following figure illustrates the relationship between the VLAN identifier, VLAN index and ACL.
282
ETHERTYPE INDEX
PROTOCOL INDEX
value received in a VLAN tagged packet. A VLAN index is the 8-bit value used to represent the VLAN asso-
ciation of the packet within the ET4148-50 device.
TCD/UDP PORT
(FROM RECEIVE PACKET)
12-bit VLAN IDENTIFIER
IP ADDRESS
VLAN INDEX
SRC/DEST
SRC/DEST
RX PORT
8
6
1
128
1
16
3
3
Vlan_Index_Table
(continued)
INDEX TABLE
ACL VLAN
LOOK-UP
PROTOCOL
IP ADDRESS
TABLE
PORT
LOOK-UP
Figure 294. ACL Processing Structure
(continued)
Figure 295. VLAN-to-ACL Mapping
6
Agere Systems - Proprietary
9
8
3
6
8-bit VLAN INDEX
Acl_Vlan_Index_Table
MAP INDEX TABLE
IP ADDRESS ACE
MAP INDEX TABLE
MAP INDEX TABLE
TCP PORT ACE
PROTOCOL ACE
10
8
7
ACE MAP TABLE
ACE MAP TABLE
PROTOCOL ACE
IP ADDRESS
MAP TABLE
TCP PORT
Vlan_Id_Table
Preliminary Data Sheet
(FOR TRANSMIT PACKET)
12-bit VLAN IDENTIFIER
64
64
64
IP SOURCE ACE MAP
IP DEST ACE MAP
IP SOURCE PORT ACE MAP
IP DEST PORT ACE MAP
PROTOCOL ACE MAP
6-bit ACL INDEX
Agere Systems Inc.
April 2006