Information Technology Reference
In-Depth Information
and provides unified configuration interface of forwarding layer to support the
designing and testing of new network experiments in future.
3.1 Labelcast Scheme
The abstraction layer of LabelCast provides five tuples
Label, Instructions,
<
Service, Status, Restrictions
as a unified and simple management interface for
LabelCast controller, which abstracts the forwarding operations and process-
ing services of the forwarding layer. In rules the label field includes label value
and options, which is the complementary of labels and indicates the method
or precondition of packet processing. The instruction field indicates forwarding
operations(e.g., lookup and modification of the base options of packets). The
service field indicates the functions of processing packets including the sequence
of service atoms(e.g., matching and modification of any packet fields, storing and
loading data).
>
a)
Instructions
: Modifying basic options of packets, and controlling packet
in
out( forwarding operations) in the fast forwarding plane.
b)
Services
: The network protocols semantics or status-related special process-
ing functions in the intelligence service plane based on the computing and
storage resources within network devices. Services abstract the characterizes
of computing and storage resources and supply the development library for
users to design applications, which is denoted by
atomService
,
atomService
= app (compResource, storeResource, pkt).
/
LabelCast utilizes
Label table
and
Cast table
to describe and manage packet
forwarding operations and services of packets processing based on the computing
and storage resources within network nodes.
c)
Label Table
: Indicates the index of packets forwarding instructions or process-
ing services on the forwarding plane, the entry contains the label and option
domain, the action command domain and service index ID field, which is
denoted by
.
d)
Cast Table
: Indicates the forwarding plane services handling packet deeply,
the entry contains the service domain, the state domain and resource con-
straints domain, which is denoted by
Labels, Instructions, ServiceID
<
>
Services, Status, Restrictions
.
<
>
After forwarding operations based on the Label table, packets could be redirected
to the target Cast table to be further processed based on protocols and status
of networks. Unlike Openflow model of pipeline, Labelcast adopts parallel pro-
cessing model controlled by multiple Cast tables, which could utilize the ability
of multi-core processors and exhibit the simplicity of run-to-completion model.
Labelcast controller manipulates the behavior of forwarding layer by configuring
the label table and the cast table with the rules.
In the rules, the label field is described by OLV
.
The offset field is the offset of the fixed-length labels in packets. OLV could
increase the flexibility of rules exchanged between the Labelcast controller and
the forwarding layer of network devices.
Offset, Length, Value
<
>
