Overview
UDP / Real-Time Traffic Errors occur when the network connection required to stream real-time data between the Softdrive client and the Cloud PC is disrupted, blocked, or degraded.
Softdrive relies heavily on UDP to deliver low-latency video, input, audio, and session keepalive traffic. Unlike TCP, UDP does not retry lost packets, which makes it faster but more sensitive to network quality and filtering.
If UDP traffic is blocked, throttled, or only allowed in one direction, the connection may fail during setup or disconnect shortly after connecting.
Common Causes
UDP / real-time traffic issues are usually caused by one or more of the following:
Firewalls or security appliances blocking UDP traffic
EDR, endpoint security, or network inspection tools interfering with UDP
VPNs or secure gateways that do not fully support bidirectional UDP
Packet loss, jitter, or unstable internet connections
UDP traffic allowed outbound but blocked inbound
These issues are network-related and are not caused by the Softdrive client or the Cloud PC itself.
Troubleshooting
Things to do when this happens:
Confirm UDP is allowed bidirectionally
Firewalls and security tools must allow UDP and TCP traffic both inbound and outbound. Allowing outbound UDP only is not sufficient. Softdrive requires the following specific TCP and UDP ports to be open and allowed in both directions between the client device and the Cloud PC.Important: UDP traffic must be allowed bidirectionally. Allowing outbound UDP only is not sufficient.
TCP (Control & Session Setup)
Direction Port Purpose Client → Server 9260 (TCP) Initial TLS connection and session setup Server → Client Ephemeral TCP response traffic UDP / SRTP (Streaming & Real-Time Data)
Direction Ports Purpose Client → Server 9250–9254 (UDP) Client-to-server real-time traffic Server → Client 58000–59000 (UDP) Server-to-client streaming, input, audio, keepalives If any of the UDP ports above are blocked, filtered, rate-limited, or only allowed in one direction, users may experience connection failures or session drops.
These ports must be allowed through:
Firewalls
EDR / endpoint security software
VPNs or secure gateways
Network inspection or traffic-shaping tools
Check network quality
Ensure the connection is stable with low packet loss and latency. Wired connections are strongly recommended.Disable VPNs or security tools for testing
Temporarily disable VPNs, traffic inspection, or endpoint protection to identify interference.Try a different network
Test from a home network or mobile hotspot to determine whether the issue is network-specific.Use the Troubleshoot option
If Softdrive previously worked on the same network, use the Troubleshoot button in the Softdrive dashboard.
Related Error Codes
The following error codes are commonly associated with UDP or real-time traffic issues:
Error Code 03 – HandshakeTimeout Session settings negotiation failed due to network instability.
Error Code 04 – KeepAliveTimeout
UDP keepalive packets timed out, causing the session to drop.Error Code 11 Severe packet loss or unstable connection detected.
Error Code 19 – connectionFailed UDP traffic required for real-time streaming is blocked or filtered.
If the issue persists after testing on a different network, please contact Softdrive Support.
When opening a support ticket, include as much detail as possible:
Exact error code(s) encountered
Timestamp of the failure
Network type (corporate, home, VPN, hotspot)
Screenshots of the error messages
Any known firewall, EDR, VPN, or UDP restrictions
Email: support@softdrive.co
Providing detailed network and security information allows the Softdrive team to quickly diagnose UDP-related issues.