Contexts and Gateways
31
IPLink Software Configuration Guide
2 • Configuration concepts
Contexts and Gateways
Context
An IPLink software context represents one specific networking technology or protocol, namely IP (Internet
Protocol). A context can be seen as virtual dedicated equipment within the IPLink. For example:
•
An IP context contains the routing functions of the IPLink. It can be thought of as an embedded router
within the IPLink
The contexts are identified by a name and contain the configuration commands that are related to the technology
they represent. A separate configuration can be built by means of the context concept for newly supported net-
work layer technologies without complicating the configuration methods of existing features. For example, as
bridging, ATM, or FR switching becomes available so a bridging, ATM, or FR context can be introduced.
Each context contains a number of interfaces, which build the connections to other IPLink software elements
and the outside world.
Figure 4
on page 30 shows one context:
•
one of type IP named router
This corresponds to the default configuration of all IPLink devices.
Note
IPLink software currently supports only one instance of the IP context types.
Example
The IP context named router can contain static routes, RIP, and NAT configuration parameters.
Interfaces, Ports, and Bindings
Interfaces
The concept of an interface in IPLink software differs from that in traditional networking devices. Tradition-
ally, the term interface is often synonymous with port or circuit, which are physical entities. In IPLink software
however, an interface is a logical construct that provides higher-layer protocol and service information, such as
layer 3 addressing. Interfaces are configured as part of a context, and are independent of physical ports and cir-
cuits. The decoupling of the interface from the physical layer entities enables many of the advanced features
offered by IPLink software.
In order for the higher-layer protocols to become active, you must associate an interface with a physical port or
circuit. This association is referred to as a binding in IPLink software. Refer to the “Bindings” section for more
information. In
figure 4
on page 30, the IP context shows three interfaces. These interfaces are configured
within their context. The bindings shown in the figure are not present when the interfaces are configured; they
are configured later.
Ports and circuits
Ports and circuits in IPLink software represent the physical connectors and channels on the IPLink hardware.
The configuration of a port or circuit includes parameters for the physical and data link layer such as line
clocking, line code, framing and encapsulation formats or media access control. Before any higher-layer user
data can flow through a physical port or circuit, you must associate that port or circuit with an interface on a
context. This association is referred to as a binding. Refer to the “Bindings” section for more information.
Содержание IPLink Series
Страница 309: ...309 Appendix B Mode summary Chapter contents Introduction 310...
Страница 312: ...Introduction 312 IPLink Software Configuration Guide B Mode summary...
Страница 325: ...325 Appendix D Internetworking terms acronyms Chapter contents Abbreviations 326...
Страница 330: ...330 Appendix E Used IP ports in the IPLink software Chapter contents Used IP ports in the IPLink software 331...