We're writing data (e.g. 350 KByte) converted into Base64 and broken down in smaller pieces (24 KByte each) from one user to another using SKYPE4COMLib.ApplicationStream.Write(String) from the latest API using Skype 3.2.0.158.

The user writing the data is finished within 10 seconds. But the receiving user receives a packet only every 20 seconds.

This causes some questions and concerns:

1) Why is it that slow in the first place?
2) If both users (sender and recipient) are in the same LAN, it's much faster. Why?
3) The application sending seem to have done their job very quickly. However, if the sender closes down the application before the recipient received the last packet, there won't be any more packets, although the Skype client remains open at both ends. Why is that?

Can anyone throw some light on this please?

I have the same problem. When Skypes have a direct conection I can get 1Mb bandwidth, but if Skype is behind a router and can't manage to open a port in the router, communication is routed through an intermediate skype as relayer and the bandwidth is limited (by skype I think.)

Yes, I think that's what's meant by in the API documentation here.

Any idea on how to open and assign a port to Skype applications though?