The CSS limit is in terms of packets...

501-1(config)# spanning-packets ?

Integer value(Range: 1-20)

501-1(config)# spanning-packets

We can hold max 20 packets per connection.

So, if you are doing L7 loadbalancing and are looking for a cookie, it better be in the first 20 packets.

ACE has a limit in buffers per connection and a limit of header size.

They are controller with a parameter-map

switch/User2(config-parammap-http)# set header-maxparse-length ?

<1-65535> Enter max-parse length for header

G.