What exactly does FastL4 profile do?

w/ CMP on the newer Intel/AMD CPUs the L4 capacity of the BIG-IP in software is the same or greater than the PVA, with more functionality (no more "this feature can't be done on the PVA"). The combination of CMP and Moore's law has allowed us to do L4 in software at the same or better rate than PVA, at less cost and less corner cases.

 

 

As far as Time to Last Byte and L4/L7, it's probably a configuration problem. Turn of nagling for starters (there's lots of threads on this in DevCentral btw). Try the "lan-optimized" TCP profile. When we measure Time To Last Byte (TTLB) of L4 verus L7 in a LAN setting it's very similar. In a WAN setting, TCPExpress (our TCP stack) can improve TTLB significantly.

 

 

BTW "faster" is a very confusing term, which is why I try to avoid using it. When someone means "faster", do they mean the capacity of the traffic manager or the time to last byte?. (The former affects the latter typically only if the traffic manager is maxed out). L4 is allows more capacity for traffic managers because we aren't doing as much useful work. But that should only matter in high throughput deployment cases (or you bought the wrong size box). TTLB is different measure.

 

 

Paul