p*m
2 楼
I found these 3 links helpful in understanding this better
https://www.bestvpn.com/guides/openvpn-tcp-vs-udp-difference-choose/
https://stackoverflow.com/questions/5485756/can-udp-retransmit-lost-data
https://stackoverflow.com/questions/107668/what-do-you-use-when-you-need-
reliable-udp
Basically, UDP is faster, and can sometimes be much faster, especially over
long distances. TCP will sent packets and then stop and wait for an
acknowledgment. Over long distances that wait time can increase. UDP does
not wait, it keeps sending packets.
You might think this would be too unreliable since files you transfer likely
won't open unless you get all the packets that carry their contents.
However, in most cases it is possible to implement a degree of reliability
on top of UDP. basically, the receiver can notice that a packet is missing
and then it can repeat the request for that packet. But there won't be the
wait time since the sender is not waiting for an acknowledgment. It keeps
sending at full speed and then from time to time it might get a request for
the same packet again. But receiving a second request does not make it wait
and be idol. But with TCP it will wait and be idol while it waits for an
acknowledgment.
There are some cases where TCP is still better. Especially when you want the
packets to arrive in the right order. There are some VPN servers that use
TCP, but for things like torrenting or streaming, speed is more important
and a lost packet can be requested again.
https://www.bestvpn.com/guides/openvpn-tcp-vs-udp-difference-choose/
https://stackoverflow.com/questions/5485756/can-udp-retransmit-lost-data
https://stackoverflow.com/questions/107668/what-do-you-use-when-you-need-
reliable-udp
Basically, UDP is faster, and can sometimes be much faster, especially over
long distances. TCP will sent packets and then stop and wait for an
acknowledgment. Over long distances that wait time can increase. UDP does
not wait, it keeps sending packets.
You might think this would be too unreliable since files you transfer likely
won't open unless you get all the packets that carry their contents.
However, in most cases it is possible to implement a degree of reliability
on top of UDP. basically, the receiver can notice that a packet is missing
and then it can repeat the request for that packet. But there won't be the
wait time since the sender is not waiting for an acknowledgment. It keeps
sending at full speed and then from time to time it might get a request for
the same packet again. But receiving a second request does not make it wait
and be idol. But with TCP it will wait and be idol while it waits for an
acknowledgment.
There are some cases where TCP is still better. Especially when you want the
packets to arrive in the right order. There are some VPN servers that use
TCP, but for things like torrenting or streaming, speed is more important
and a lost packet can be requested again.
p*m
3 楼
根本不需要vpn
gmail工作的很好 所以都可以 mitbbs也没问题
gmail工作的很好 所以都可以 mitbbs也没问题
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