I
Ian
Hello,
I could use some help troubleshooting issues with Windows XP Remote
Assistance (providing remote assistance via the Internet).
Environment for Expert (User Providing Remote Assistance):
- Windows XP Professional with All Critical Updates Applied
- MSN Messenger 6.1.0207 (latest)
- Firewall: SMC 7004VBR Barricade Cable/DSL Broadband Router; latest
firmware
(this is a hardware firewall that supports UPnP traversal)
Environment for Client (User Requesting Remote Assistance)
- Windows XP Home with All Critical Updates Applied
- MSN Messenger 6.1.0207 (latest)
- Firewall: Built-in Internet Connection Firewall (ICF)
Problem Scenario:
1. Client & Expert are both running MSN Messenger.
2. Client issues request for Remote Assistance via MSN Messenger.
3. Expert accepts request for Remote Assistance.
4a. If client has ICF enabled, Remote Assistance session CANNOT be
established.
4b. If client has ICF disabled, Remote Assistance session CAN be
established.
Troubleshooting:
Looking in the Client's system event log, I find the following events
(summarized for presentation here):
Event Type | Event Source | Event ID | User |
Description
#1: Information | Service Control Manager | 7035 | NT AUTHORITY\SYSTEM |
"The Remote Desktop Help Session Manager service was successfully
sent a start control."
#2: Information | Service Control Manager | 7036 | N/A |
"The Remote Desktop Help Session Manager service entered the running
state."
#3: Information | Remote Desktop Help Session Manager | 18 | N/A |
"User <machine>\<username> has started a Remote Assistance
connection to 192.168.0.100"
#4: Error | TermDD | 50 | N/A |
"The RDP protocol component X.224 detected an error in the protocol
stream and has disconnected the client."
Analysis
As you can see in message #3, the client machine has received my "internal"
/ "non-routable" (LAN) IP address rather than my router's "external" /
"public" (WAN) IP address and that's obviously why it cannot complete the
handshake process. It appears to be a breakdown in UPnP somewhere - either
in the traversal of my UPNP-enabled firewall or with how things are
interpreted on the Client's computer by ICF.
To further complicate matters, the scenario described DID work as little as
one week ago. And, it continues to work for two OTHER similarly-configured
Client computers even now.
I can provide further information on troubleshooting steps taken upon
request...
Any suggestions? From the experts (MS-MVPs) ONLY please unless you know
what UPnP traversal is, what ICF does, and the difference between routable &
non-routable IP addresses.
Thanks,
Ian
I could use some help troubleshooting issues with Windows XP Remote
Assistance (providing remote assistance via the Internet).
Environment for Expert (User Providing Remote Assistance):
- Windows XP Professional with All Critical Updates Applied
- MSN Messenger 6.1.0207 (latest)
- Firewall: SMC 7004VBR Barricade Cable/DSL Broadband Router; latest
firmware
(this is a hardware firewall that supports UPnP traversal)
Environment for Client (User Requesting Remote Assistance)
- Windows XP Home with All Critical Updates Applied
- MSN Messenger 6.1.0207 (latest)
- Firewall: Built-in Internet Connection Firewall (ICF)
Problem Scenario:
1. Client & Expert are both running MSN Messenger.
2. Client issues request for Remote Assistance via MSN Messenger.
3. Expert accepts request for Remote Assistance.
4a. If client has ICF enabled, Remote Assistance session CANNOT be
established.
4b. If client has ICF disabled, Remote Assistance session CAN be
established.
Troubleshooting:
Looking in the Client's system event log, I find the following events
(summarized for presentation here):
Event Type | Event Source | Event ID | User |
Description
#1: Information | Service Control Manager | 7035 | NT AUTHORITY\SYSTEM |
"The Remote Desktop Help Session Manager service was successfully
sent a start control."
#2: Information | Service Control Manager | 7036 | N/A |
"The Remote Desktop Help Session Manager service entered the running
state."
#3: Information | Remote Desktop Help Session Manager | 18 | N/A |
"User <machine>\<username> has started a Remote Assistance
connection to 192.168.0.100"
#4: Error | TermDD | 50 | N/A |
"The RDP protocol component X.224 detected an error in the protocol
stream and has disconnected the client."
Analysis
As you can see in message #3, the client machine has received my "internal"
/ "non-routable" (LAN) IP address rather than my router's "external" /
"public" (WAN) IP address and that's obviously why it cannot complete the
handshake process. It appears to be a breakdown in UPnP somewhere - either
in the traversal of my UPNP-enabled firewall or with how things are
interpreted on the Client's computer by ICF.
To further complicate matters, the scenario described DID work as little as
one week ago. And, it continues to work for two OTHER similarly-configured
Client computers even now.
I can provide further information on troubleshooting steps taken upon
request...
Any suggestions? From the experts (MS-MVPs) ONLY please unless you know
what UPnP traversal is, what ICF does, and the difference between routable &
non-routable IP addresses.
Thanks,
Ian