 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| n |
most
effort spent on direction FH->MH
|
|
|
|
– |
authors
argue that not much can be done for MH->FH
|
|
|
|
n |
losses
occur over first link, the unreliable wireless link
|
|
|
| n |
Internet
drops 2%-5% of IP packets, tendency rising
|
|
|
|
– |
assume
that IP packet is lost in wired part of network:
|
|
|
|
n |
receiver
(FH) will issue duplicate ACKs
|
|
|
|
n |
this
should trigger fast retransmit rather than slow start (?)
|
|
|
|
n |
nothing
is done to ensure that ACKs are not dropped over last link
|
|
|
|
n |
retransmission
of data packet over wireless link is subject to unreliable
|
|
|
link
and low bandwidth again
|
|
|
|
– |
Snoop
could potentially benefit from caching packets in both
|
|
|
directions
|
|
|
|
n |
how
would this differ from link-layer retransmission policy?
|
|
