
2.4.1.1. Area 1 IP Addressing Host Private Network
The host location private IP network is the private network in which the host is located.
For non-IP host communications, this network is part of the IPSec router terminating the
tunnels. This network typically exists prior to an MRM deployment, and IP network
addressing has been assigned by a network design engineer or administrator, typically
using IP Address for private Internets as described in RFC 1918. The corporate host
and any other service hosts, including management hosts and their respective IP
networks, must be visible to the "remote" device network (Area 5) through the IPSec
tunnel.
2.4.1.2. Area 2 IP Addressing Tunnel Termination
The device(s) in area 2 must be directly connected, or reachable to the IP host in area
1. In addition, the IPSec tunnel terminating device in area 2, must have an IP address
acting as a tunnel peer to the remote MRM devices, and must be reachable through the
CDMA or GSM network. This IP address is normally assigned by the carrier, to ensure
reachability across the carrier’s network to the remote MRM. However, carriers now
offer MPLS Private VPN networks which provide for client-specific IP addressing. If the
carrier assigns the IP addressing, the carrier will typically assign a small IP network
from their IP address space, with a 29- or 30-bit mask. One host from within this
network must act as the IPSec tunnel peer. This network can be assigned on a physical
interface, or a logical (loopback) interface.
2.4.1.3. Area 3 IP Addressing Frame Relay/MPLS Access Point
Frame Relay/MPLS is typically used to connect the host network to the carrier. A
customer can use an existing frame relay/MPLS circuit. Prior to the introduction of
MPLS circuits, a PVC connection to the carrier was required, or in some cases, a
completely new frame relay line was used, with a PVC connection to the carrier. This
determination is made during the design stage of a network. The carrier will assign an
IP subnet for use on the frame relay PVC, typically with a 30-bit mask, providing for one
IP at the client router for the PVC, and one IP at the carrier’s router for the same PVC.
For routing purposes, the IP address assigned to the carriers router, becomes the
gateway address to reach Area 4 IP networks (MRM radio IP addresses). This address
is used for static routing purposes in the client frame relay router, as the next hop
address to reach the distant MRM IP range (Area 4). Routing protocols are not
permitted on the frame relay link between the client and carrier. Frame relay DLCI
numbers are assigned by the frame relay carrier responsible for the PVC link between
the client and the carrier, and are made available when the PVC order is complete.
Note: Recently Carriers have migrated away from Frame Relay and are now only
offering Private VPN Tunnels over MPLS Circuits.
2.4.1.4. Area 4 IP Addressing MRM Radio IP
In both GSM and CDMA networks, the IP address assigned to the radio device
connecting to the carrier network is made dynamically. The IP addresses are
determined by the carrier, and assigned to the modem dynamically during connection
time. In both CDMA and GSM networks, the modems connect to the network using the
PPP protocol, and are assigned IP addresses during this connection setup. IP