Choosing a Segment Size
Never want to send segments longer than peer’s MSS, but what about smaller:
- if larger than path MTU, may fragment
- if smaller than path MTU, inefficient
Recall, we may use path MTU discovery:
- set DF bit in IP header of each packet
- look for ICMP unreachable messages; newer ones contain next-hop MTU
- if lacking that, just choose common sizes…