3 ms·
Aren't TCP ACKs 20 bytes by themselves? The 40 byte total includes IP, which would not be needed if running on ATM, right?
by jzwinck 8y ago
Aren't TCP ACKs 20 bytes by themselves? The 40 byte total includes IP, which would not be needed if running on ATM, right?
- tlb 8y agoIn most uses of ATM, a single VC (virtual circuit) carries all the data between a pair of switches. The protocol to set up a new VC is pretty expensive, so it's impractical to set up a VC for each TCP connection or even between each pair of endpoint hosts. So mostly, VCs carry a stream of packets between switches, each with their own header.
- jzwinck 8y agoIn that case doesn't it mean there are 40 bytes of TCP/IP headers and 5 bytes of ATM headers plus a mere 8 bytes of payload per TCP packet?
- toast0 8y agoATM packets (cells?) are fixed size, but you can fragment higher level protocols across them. It's not common to run IP level fragmentation down to ATM sizes.