The RDP protocol component X.224 detected an error

[Tony]

This has been reported many times but neither here not in MS KB could I
find anything relevant for this error happening between two XP SP2
Professional machines, both recently updated with everything that MS
considers worthy of updating..

 

[Tony]

Let me add that there is no problem remotely connecting from machine A
to machine B, both on local LAN.

However, accessing machine B from machine C via WAN gives the error
above. All three machines run XP Professional SP2 with the latest
updates.

Additionally, RDP port has been changed via Registry Editor because
machine C is behind the firewall that blocks default RDP port. This
does not seem to be the problem since local LAN connection using "B
machine name:new port" on RDS client prompt works fine.

 

[Peter]

Let me add that there is no problem remotely connecting from machine A

to machine B, both on local LAN.

However, accessing machine B from machine C via WAN gives the error
above. All three machines run XP Professional SP2 with the latest
updates.

Additionally, RDP port has been changed via Registry Editor because
machine C is behind the firewall that blocks default RDP port. This
does not seem to be the problem since local LAN connection using "B
machine name:new port" on RDS client prompt works fine.

Poor WAN connectivity? (Latency, packet drops, packet fragmentation?)

 

[Tony]

Poor WAN connectivity? (Latency, packet drops, packet fragmentation?)

Possible but other people, from the same location, have no problems
establishing RDP sessions with their remote PCs. In one case, we are
even using the same ISP on remotes.

We also tried the following: a person who established connection to his
remote PC with no problems then tried connecting from within his remote
session to my remote machine and it worked. But he can not do the same
thing directly, i.e. connecting from his local to my remote machine.

I know that different WAN segments are in question but it does make it
harder to believe that poor WAN connectivity is at play.

 

[Tony]

Followup for those who have the same problem:
I never managed to figure out what exactly is going on. I tried free
veriosn of Real VNC and it didn't work either. Real VNC and Windows
Event logs were showing that incoming connections were established but
then closed by the VNC server (probably due to timeout). This gave me a
hint that the problem is probably not on remote server
software/configuration side.

Friends connecting to their remotes from my local machine pretty much
excluded similar problems with the local machine.

I then decided to upgrade my old broadband Linksys router to wireless
Linksys WRT54GL and, all of sudden, RDP connection started working just
fine. Router is still connected to RDP server via LAN cable, so
wireless connection doesn't play a role - probably just having a newer
hardware/firmware helped.