how to test connection migration in win10 env?

[bigoceanan]

hi everyone,
i just built the msquic lib in win10 platform with quictls-openssl and the samplequic can run.
now i want to test connection migration by msquic. for example i change network from wifi to mobilephone 4g when the session has been established, and i wish the connection can't be closed and the cid (quic connetion id) is same. i want to check PATH_CHALLENGE package in wireshark.
so anyone can tell me which demo test can support this function? or give me some code *.c.
thanks a lot.

[guhetier]

Look at QUIC_PARAM_CONN_LOCAL_ADDRESS to trigger a connection migration on the client side.
This is not part of the basic sample and is probably out of the scope of a basic demo code.

i wish the connection can't be closed and the cid (quic connetion id) is same.

A new CID is used on a new path, per the QUIC spec. A CID must not be re-used between paths.

[bigoceanan]

hi guhetier，
Thanks for your reply.
You mean I need to change the connection QUIC_PARAM_CONN_LOCAL_ADDRESS to new ip:port ?
How to know the network interface be changed in quic-app? then I need to do 0-rtt connetion with current ticket/token?
I'm a freshman in quic tech，pls give me more detail about this.
Thanks again.

[guhetier]

That is up to the app, MsQuic currently doesn't provide support for it. Different Windows APIs can provide the recommended interface, assuming they can route to the target address.
Maybe https://learn.microsoft.com/en-us/uwp/api/windows.networking.connectivity.networkinformation.getinternetconnectionprofile?view=winrt-26100 or https://learn.microsoft.com/en-us/windows/win32/api/iphlpapi/nf-iphlpapi-getbestinterface?redirectedfrom=MSDN can get you started. I am not an expert on this topic though, and determining which interface is best can be tricky.

You don't need 0-rtt, migrating a connection doesn't not interrupt it. 0-rtt is about resuming a connection after a disconnection.

[bigoceanan]

OK, i will do some research to your suggestion and let you know if any progress.
tks for your so quick reply.

[bigoceanan]

Look at QUIC_PARAM_CONN_LOCAL_ADDRESS to trigger a connection migration on the client side. This is not part of the basic sample and is probably out of the scope of a basic demo code.

i wish the connection can't be closed and the cid (quic connetion id) is same.

A new CID is used on a new path, per the QUIC spec. A CID must not be re-used between paths.

hi @guhutire，
I found your interaction with @masa-koz and @nibanks in [Support Client Migration (Client Side)#4218]
#4218
If this pull be megered into master, the msquic lib will automatic sensing and triggering when changing in the physical network，so I will not need to set or change QUIC_PARAM_CONN_LOCAL_ADDRESS in my client prog?
Or I have to explicitly call function/setting for QUIC_PARAM_CONN_LOCAL_ADDRESS regardless of whether this feature is supported or not ？
pls give me some advice.

[guhetier]

This PR needs to be reviewed, and is complex enough I couldn't find time to work on it yet. I can't tell you yet what it can or can't do. I hope to get to it when possible.