DHCP—Dynamic Host Configuration Protocol. DHCP is a protocol that delivers IP addresses and configuration information to network
GGSN—Gateway GPRS Support Node. A wireless gateway that allows mobile cell phone users to access the public data network (PDN)
or specified private IP networks. The GGSN function is implemented on the Cisco routers.
GLBP—Gateway Load Balancing Protocol. Provides automatic router backup for IP hosts that are configured with a single default
gateway on an IEEE 802.3 LAN. Multiple first-hop routers on the LAN combine to offer a single virtual first-hop IP router
while sharing the IP packet forwarding load. Other routers on the LAN may act as redundant (GLBP) routers that will become
active if any of the existing forwarding routers fail.
GPRS—General Packet Radio Service. A 2.5G mobile communications technology that enables mobile wireless service providers to offer
their mobile subscribers with packet-based data services over GSM networks.
GSM network—Global System for Mobile Communications network. A digital cellular technology that is used worldwide, predominantly in Europe
and Asia. GSM is the world’s leading standard in digital wireless communications.
Home Agent—A Home Agent is a router on the home network of the Mobile Node (MN) that maintains an association between the home IP address
of the MN and its care-of address, which is the current location of the MN on a foreign or visited network. The HA redirects
packets by tunneling them to the MN while it is away from the home network.
HSRP—Hot Standby Router Protocol. Provides high network availability and transparent network topology changes. HSRP creates a
Hot Standby router group with a lead router that services all packets sent to the Hot Standby address. The lead router is
monitored by other routers in the group, and if it fails, one of these standby routers inherits the lead position and the
Hot Standby group address.
IPCP—IP Control Protocol. The protocol used to establish and configure IP over PPP.
LCP—Link Control Protocol. The protocol used to establish, configure, and test data-link connections for use by PPP.
PDSN—Packet Data Serving Node. The Cisco PDSN is a standards-compliant, wireless gateway that enables packet data services in
a Code Division Multiplex Access (CDMA) environment. Acting as an access gateway, the Cisco PDSN provides simple IP and Mobile
IP access, foreign-agent support, and packet transport for Virtual Private Networks (VPN).
PPP—Point-to-Point Protocol. Provides router-to-router and host-to-network connections over synchronous and asynchronous circuits.
PPP is most commonly used for dial-up Internet access. Its features include address notification, authentication via CHAP
or PAP, support for multiple protocols, and link monitoring.
VRF—VPN routing and forwarding instance. A VRF consists of an IP routing table, a derived forwarding table, a set of interfaces
that use the forwarding table, and a set of rules and routing protocols that determine what goes into the forwarding table.
In general, a VRF includes the routing information that defines a customer VPN site that is attached to a provider edge router.
VRRP—Virtual Router Redundancy Protocol. Eliminates the single point of failure inherent in the static default routed environment.
VRRP specifies an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers
on a LAN. The VRRP router that controls the IP addresses associated with a virtual router is called the master, and forwards
packets sent to these IP addresses. The election process provides dynamic failover in the forwarding responsibility should
the master become unavailable. Any of the virtual router IP addresses on a LAN can then be used as the default first-hop router
by end hosts.