Description

This article describes the issue of the Sierra Wireless Aircard 319U 3G USB modem occasionally not working, when connected to a SRX device.

Symptoms

When the Sierra Wireless Aircard 319U 3G USB modem is connected to a SRX device and used for network access in 3G mode (UMTS, HSPA, HSPA+,...), it may occasionally stop forwarding traffic. In this scenario, only the restarting of the interface or SRX device helps to recover traffic. At times, if left running for a longer time in the bad state, the modem may start forwarding traffic again by itself.

The issue was reproduced by running a ping from the SRX device over the 3G interface for a few minutes, stopping the ping for 2 minutes, and then trying to run it again. After the first ICMP packet, it would fail and block all further traffic. No other traffic was present during the test.

Solution

This bug was observed with 319U modems that were running firmware 2_0_5. This issue is due to a problem in the modem firmware.

  • This bug is resolved in 319U 2_0_8 or later firmware.
  • The firmware can be obtained from Sierra Wireless.
  • The Recommended file to upgrade a 319U USB modem via a Windows PC is N2.0-Release6-N2_0_8_6BT-N2_0_8_6AP.exe .