Application problems

Review the frequently asked questions and answers about problems with applications.

Browse these questions, then link to the following answers.

  1. Applications do not respond and there is packet loss. What do I do?
  2. Application connections, such as HCL Sametime, seem to disconnect unexpectedly. What do I do?

Answers to the problems with applications include:

  1. Applications do not respond and there is packet loss. What do I do?

    Using the SafeLinx Administrator, navigate to the Logging tab of the SafeLinx Server resource properties. From here set the log levels to DEBUG, ERROR, LOG, Trace-IP, WARNING. Having this level of logging active will allow either the administrator or HCL Support to view the traffic as it arrives at the SafeLinx Server and verify if the packet is sent to the TCP/IP stack of the operating system for delivery as well as any return traffic. Once the log levels are set as suggested, attempt to recreate the issue. Sometimes it is important to have a matching set of log files from both the SafeLinx Client and the SafeLinx Server to match up packets. You might need to tune your network for performance. Make sure that settings between the SafeLinx Server and the SafeLinx Client match and are optimized for your network. For example, match MNC settings such as network MTU and TCP retransmit time-to-live and connection profile settings such as compression algorithm, protocol header reduction, TCP protocol optimization, and fragmentation. See Tuning SafeLinx Server for more detail.

  2. Application connections, such as HCL Sametime, seem to disconnect unexpectedly. What do I do?

    Try fixing the problem by using the Keepalive Interval with an initial value of 10 seconds for a slower (2G/3G) public cellular network. For other connections, such as WLAN or broadband, try setting the value to 15 seconds. The Keepalive value might help to prevent the Bearer Network from disconnecting the connection from the device to the network. The SafeLinx Client maintains its virtual circuit to the SafeLinx Server, but in the absence of traffic, often cellular networks will disconnect the device in a short amount of time.

    This value varies up or down depending on the network address translation (NAT) and firewall characteristics of your ISP or network service provider. The setting for your network requires trial and error to determine the correct value.

    Inbound voice call handling on some devices can be affected by active data connections such as used by the SafeLinx Client. Connections which are defined to use the network interface Automatically Connect usually allows inbound voice calls to occur. These calls occur provided data is not being sent at the time the call is received. Know that the Keepalive setting, which causes the client to send Keepalive packets at configured intervals, can prevent the phone from receiving inbound voice calls. The probability of Keepalive packets interference with inbound voice calls increases as the configured Keepalive interval decreases.