Is the port mapping same as port forwarding?
Yes, both terms are used interchangeably and mean the same thing.
Does the reserve IP address capability negate the need for the no-ip.com service?
No. Reserving an IP address is a means to instruct the DHCP service on the router to "save" a specific Private IP address for a device on the local network. No-IP.com is a service that basically tracks the dynamic Public IP address of your modem or router and provides you with a "static" URL address to access it from the Internet. A similar service to No-IP.com would be
DynDNS.
Accessing a server on the local network from a remote client would require that the client knows the Public IP address and port(s) required to access that server. Servers, like yours that are behind a firewall, must either use port mapping (port forwarding) or be configured to be in a DMZ which would completely expose them to the Internet. Port mapping reduces that risk to only allow predefined ports to be open to the Internet.
Since most consumers have Internet service with comes with a dynamic (changing) Public IP address, just knowing what it is at any given time won't help in the long run. This is where services, like No-IP come in. Typically they will give you a client utility that you would run on your computer. This utility will provide them with an update every time your ISP changes your Public IP address ... or you may be required to do this manually. They will also provide you with a URL to use instead of using the Public IP address.
To setup port mapping on an 802.11n AirPort Extreme Base Station (AEBSn), either connect to the AEBSn's wireless network or temporarily connect directly, using an Ethernet cable, to one of the LAN port of the AEBSn, and then use the AirPort Utility, in Manual Setup, to make these settings:
1. Reserve a DHCP-provided Private IP address for the Filemaker Pro server.
Internet > DHCP tab
o On the DHCP tab, click the "+" (Add) button to enter DHCP Reservations.
o Description: <enter the desired description of the host device>
o Reserve address by: MAC Address
o Click Continue.
o MAC Address: <enter the MAC hardware address of the host computer's Ethernet or wireless depending on how it accesses the network>
o IPv4 Address: <enter the desired Private IP address you want to assign to the host>
o Click Done.
2. Setup Port Mapping on the AEBSn.
Advanced > Port Mapping tab
o Click the "+" (Add) button
o Service: <choose the appropriate service from the Service pop-up menu or leave blank>
o Public UDP Port(s): <enter the appropriate UDP port values>
o Public TCP Port(s): <enter the appropriate TCP port values>
o Private IP Address: <enter the IP address of the host server>
o Private UDP Port(s): <enter the same as Public UDP Ports or your choice>
o Private TCP Port(s): <enter the same as Public TCP Ports or your choice>
o Click "Continue"
