Upgraded to OpenVPN 1.2.5 (iOS): TCP protocol not stable on v1.2.5

vipp

After I upgraded my iOS app to v1.2.5, I found the TCP stream is much unstable than before. Whatever I put the server behind a proxy, or connected directly by TCP protocol. (Well-tested on 4G mobile network and Wi-Fi)

Checked with the log and the reason of disconnecting is, a transport error (NETWORK_EOF_ERROR) was happened. I did lots of test with the same server, same network environment and the same client profile. TCP protocol worked well on v1.1.x but randomly disconnected on v1.2.5. UDP protocol worked well on both v1.1.x and v1.2.5.

I also checked the release note of v1.2.5 and fount "converted VPN backend to new Apple Network Extensions
framework". I am not sure if this would be the root cause of the unstable issue.

I hope the iOS team can fix this TCP unstable issue soon in next release. If it is not easy, I also suggest the iOS team to release this 2 series as a separate new app which can be named OpenVPN Connect 2 or something like that, and keep the 1 series as the original one. That people can choose a suitable version rather than being enforced to upgrade to the latest version.

ordex

vipp wrote After I upgraded my iOS app to v1.2.5, I found the TCP stream is much unstable than before. Whatever I put the server behind a proxy, or connected directly by TCP protocol. (Well-tested on 4G mobile network and Wi-Fi)

Thanks for reporting your issue. Would you be able to take a traffic dump of the connection so that we can observe what happens when it stops?
Do you have any easy way to reproduce the problem?

vipp wrote Checked with the log and the reason of disconnecting is, a transport error (NETWORK_EOF_ERROR) was happened. I did lots of test with the same server, same network environment and the same client profile. TCP protocol worked well on v1.1.x but randomly disconnected on v1.2.5. UDP protocol worked well on both v1.1.x and v1.2.5.

I also checked the release note of v1.2.5 and fount "converted VPN backend to new Apple Network Extensions
framework". I am not sure if this would be the root cause of the unstable issue.

The NE Framework is not responsible for the transport layer (where the UDP/TCP connection is established), therefore I don't think the problem is there.

vipp wrote I hope the iOS team can fix this TCP unstable issue soon in next release. If it is not easy, I also suggest the iOS team to release this 2 series as a separate new app which can be named OpenVPN Connect 2 or something like that, and keep the 1 series as the original one. That people can choose a suitable version rather than being enforced to upgrade to the latest version.

Sorry, but as mentioned in other threads, we can't release the old app anymore. The old API is not accepted by Apple anymore in new submissions.

However, if you provide enough information we can try to identify the issue and then think about a fix.

Let us know!

Thanks

vipp

Thanks for the kindly reply. I am glad to help to find out the cause, and provide you more information as much as possible.

ordex wrote
vipp wrote After I upgraded my iOS app to v1.2.5, I found the TCP stream is much unstable than before. Whatever I put the server behind a proxy, or connected directly by TCP protocol. (Well-tested on 4G mobile network and Wi-Fi)
Thanks for reporting your issue. Would you be able to take a traffic dump of the connection so that we can observe what happens when it stops?
Do you have any easy way to reproduce the problem?

I don't know how to dump the traffic from iOS device but I think I can do this on the server side. Is the raw data from tcpdump good for you? Or any utility you suggest.

The unexpected disconnecting often happens on a large throughput (e.g. play a video clip). For example I played 5 videos and it happens about 2 times, more or less. That's an easy way to reproduce this problem.

ordex

vipp wrote I don't know how to dump the traffic from iOS device but I think I can do this on the server side. Is the raw data from tcpdump good for you? Or any utility you suggest.

Yes, absolutely. A pcap file is what works best.

vipp wrote The unexpected disconnecting often happens on a large throughput (e.g. play a video clip). For example I played 5 videos and it happens about 2 times, more or less. That's an easy way to reproduce this problem.

Ok, this may help reproducing the issue here.

However, now that 1.2.6 is out. Would you mind trying reproducing the issue there first?
If it still persist, could please open a ticket in our trac system and attach the dump?
Check this post to learn how: https://forums.openvpn.net/viewtopic.php?f=36&t=25650

Thanks!

ordex

A similar problem has been reported here: https://community.openvpn.net/openvpn/ticket/980 therefore I am closing this thread. We can continue tracking the bug there.