WAN Backhaul Deployment Considerations

Before defining a profile‘s WAN Backhaul configuration refer to the following deployment guidelines to ensure these configuration are optimally effective:

• If the WAN card does not connect after a few minutes after a no shutdown, check the access point‘s syslog for a detected ttyUSB0 No such file event. If this event has occurred, linux didn‘t detect the card. Re-seat the card.
• If the WAN card has difficulty connecting to an ISP (syslog shows that it retries LCP ConfReq for a long time), ensure the SIM card is still valid and is plugged in correctly.
• If a modem doesn‘t responding with an OK during the dialing sequence, the WAN card is in an unknown state and will not accept a command. Re-seat the card and begin the dialup sequence again until the card is recognized.
• If encountering a panic when conducting a hotplug, power off the access point for one minute. The access point could continue to panic or detect the descriptor of the last utilized WAN card. Thus, it's a good idea to clear the panic state by temporarily disconnecting then re-applying access point power.
• If wanting to unplug the WAN card, ensure sure you shutdown first, as the probability of getting a panic is reduced. With the new high-speed WAN cards currently being utilized, the chances of getting a panic significantly increase.