They are different tables, implemented in two different kernel drivers. The following applies to R80.10 and earlier gateway.
SecureXL uses one instance of the simmod (SecureXL Implementation Module) driver, and connections are tracked through the cphwd_db table maintained in SecureXL. There are several other individual tables SecureXL maintains as part of its overall state table, which are documented in section 7 here: sk98722: ATRG: SecureXL
Firewall Workers have one instance of the fw_X kernel driver (sometimes called INSPECT driver/engine) per defined worker/kernel instance, and tracks connections through the shared "connections" table which is only one component of the overall state table. Best description of the contents of the connections table is here: sk65133: Connections Table Format
Initially all new connections arrive at the SecureXL driver inbound, then go through the Firewall Path (F2F) for an initial Firewall policy lookup, and if they are accepted an entry is added to the "connections" state table. When the packet leaves the INSPECT driver on the outbound side, the accepted packet passes through SecureXL and a connection entry is created in the cphwd_db table for future tracking.
The maximum size of the SecureXL cpwd_db table matches the maximum set for the connections table (FW Object...Optimizations...Capacity Optimization...Calculate the maximum limit for concurrent connections), but note that each individual connection is tracked as at least two separate flows of packets (c2s/outbound, s2c/inbound) and if the connection is NATted there are four separate flows being tracked (c2s/outbound pre-NAT, c2s/outbound post-NAT, s2c/inbound pre-NAT, s2c/inbound post-NAT). This is why the reported number of connections (actually "flows") by fwaccel conns (SecureXL) or fw tab -t connections (INSPECT) may appear to be much higher than the number of "connections".
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