Sim Card Is Blocked; Remote Connections; Radio Band Selection - Sierra Wireless AirLink ES440 User Manual

Rev 1 Nov.14
• Move the antenna away from noisy equipment.
• Move closer to the nearest cell tower line of sight, or further away from the
interfering cell tower.

SIM Card is Blocked

My SIM card has a PIN number. I've entered the wrong PIN several
times and now the SIM card is blocked.
AirLink products do not support Personal Unlocking Key (PUK) entry. However, if
you need to unblock the SIM card:
1. Contact your Mobile Network Operator to obtain the PUK.
2. Remove the SIM card from the AirLink device and insert it in a cell phone that
accommodates a MiniSIM (2FF) card.
3. Enter the PUK to unblock the SIM card and then return the SIM card to the
AirLink device.
Note: Be careful when entering the PUK. You have a limited number of attempts to enter
the correct PUK (generally 10) before the SIM card is permanently disabled and a new SIM
card is required. If the PUK does not unblock the SIM card after the first few attempts,
contact your Mobile Network Operator.

Remote connections

I cannot connect to the AirLink device remotely over the Mobile
Network Operator's Private Network via the Web UI, although I can
connect to it locally.
Some Mobile Network Operators' private networks have restrictions on the
maximum transmission unit (MTU) size. This is more prevalent with LTE networks.
Possible solutions:
• Use your Mobile Network Operator's public network.
• Ask your Mobile Network Operator to reduce the MTU size on the router or
other equipment at their end of the private network. Setting the MTU value
below 1500 bytes (for example 1326 bytes) has resolved the problem on
some private networks.
• If your AirLink device has a radio module (such as the MC7700 or MC7750)
that supports LTE networks, select an option in ACEmanager (WAN/
Cellular > Advanced > Setting for Band field) that excludes LTE networks.

Radio Band Selection

I set the radio band in the UI (WAN/Cellular > Setting the Band) or by
using the AT!BAND AT command, but after I reboot the band setting
reverts to its former value.
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