Rainbow Electronics W90N740 - Manual (Page 75)

W90N740
Publication Release Date: November 26, 2004
- 71 - Revision A4
NH_Err: No Hit Error
These bits records error status if NAT processing error is occurred and are wrote by NATA.
(1) UCK_Err: TCP = 1 and UCKS = 1
(2) TU_Err: TCP = 1 and UDP = 1
(3) NH_Err: No hit error
IP Header Length: TCP/UDP header location offset
The offset value lets the NAT accelerator to identify the starting address of TCP or UDP header, which
is used for NAT to parsing port data. The value is valid if Hit is set.
Hit Entry Number: the entry number hit with the input address
The value indicates which entry is hit to let NAT accelerator to take corresponding data. The value is
valid if Hit is set.
PPPCaps: PPPoE datagram encapsulated
The value is 1 if PPP encapsulation is used (8 bits protocol field), and 0 if encapsulation is not used
(16 bits protocol field).
PPPoE: PPPoE protocol
The value is 1 if the packet takes PPPoE protocol instead of IP protocol. The value is 0 if the packet
takes IP protocol.
UCKS: UDP protocol with skip checksum replacement
The value is 1 if the packet takes UDP protocol, and its checksum is zero. The NAT accelerator will
skip the checksum replacement procedure.
UDP: apply UDP protocol
It tell NAT engine to apply UDP protocol. The value is 1 if the packet takes UDP protocol, and 0 if the
packet takes non-UDP protocol. The value is valid if Hit is set.
TCP: apply TCP protocol
It tell NAT engine to apply TCP protocol. The value is 1 if the packet takes TCP protocol, and 0 if the
packet takes non-TCP protocol. The value is valid if Hit is set.
L/W: hit port; the value is 1 if internal (LAN) port gets hit, and 0 if external (WAN) port is hit
The S/W program must specify LAN port and WAN port with the two EMCs. For example, EMC 0 is
connected to WAN port, and EMC 1 is connected to LAN port. If NAT is enabled, EMC 0 is connected to
external port for {MA, MP} comparison, and EMC 1 is connected to internal port for {LA, LP} comparison.
The L/W value is 1 if the hit port is internal port, and 0 if the hit port is external port. The value is valid if
Hit is set.