===== AT&T MicroCell Troubleshooting =====

If the AT&T 3G MicroCell is not working after being connected to the router/gateway, first try the basic troubleshooting steps contained in the User Guide.  If the 3G MicroCell still will not connect to the AT&T network (as indicated by a continuous blinking 3G light), then use the following instructions to check the router's settings and change them, as needed. If it is a router CalTel has provided these settings should be in place all ready by default.
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Normally, just plugging the 3G MicroCell into the router/gateway is all that is required. However, sometimes router/gateway settings have been changed or the 3G MicroCell will not connect properly.  This section will show how to change the settings for some popular modems/routers to enable the 3G MicroCell to connect successfully.
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Configure the network to allow the following if using other than CalTel provided equipment or custom settings:

   - DHCP is on
   - Port Blocking is either turned off or allowing ports 4500 and 500
   - MTU size is set to *1492*
   - MAC address filtering is either turned off or allowing the MAC address of the AT&T 3G MicroCell
   - IPSec Pass-Through is **Enabled**
   - Block Fragmented Packets is **Disabled**
   - If using multiple routers, the 3G MicoCell must be connected to the first router connected to the broadband modem
   - If the 3G MicroCell is connected to a router that is connected to a modem and both the router and the modem have NAT (Network Address Translation) enabled, disable NAT either in the router or the modem.
   - Ensure the modem / router is using the latest software (firmware). Please see the manufacturer's documentation.
   - TCP/UDP Ports\\ **NOTE:  All ports listed need to be configured for inbound and outbound connections.**
     - **123/UDP**: NTP timing (NTP traffic)
     - **443/TCP**: Https over TLS/SSL for provisioning and management traffic
     - **4500/UDP**: IPSec NAT Traversal (for all signaling, data, voice traffic)
     - **500/UDP**: IPSec Phase 1 prior to NAT detection (after NAT detection, 4500/UDP is used)
     - **4500/UDP**: After NAT detection, 4500/UDP is used