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The various research
endeavors associated with this project are described as follows:
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SELFCON – An Architecture
for Self-Configuration of Networks
The manual processes
presently involved with network management are quickly reaching their limits
as networks become more complex and implement emerging services. SELFCON is
an architecture that combines several techniques such as object modeling
using the standard DEN specification, directory services, and network
programming to provide self-configuration of networks. This feature of
self-configuration addresses several configuration issues encountered in the
most commonly used configuration methods and protocols, such as CLI, SNMP
and COPS.
The configuration information
is maintained in a standard directory. The configuration information
maintained in the directory is modeled using the standard DEN specification.
The network elements register for change notification at the directory
server using a directory service. The directory server notifies the network
elements about any related changes in the configuration information. The
network elements upon receiving the changed configuration data are able to
perform self-configuration.
SELFCON allows increased
scalability, as the network elements are able to automatically adapt
themselves to the new configuration policies. SELFCON is able to eliminate
configuration inconsistencies, reduce configuration management tasks, and is
able to provide a unifying framework for effective enterprise management.
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META POLICY INFORMATION
BASE
Policy-based networking (PBN)
has emerged as a promising paradigm for network operation and management. It
is based on high-level control/management policies, that is, rules that
describe the desired behavior of the network in a way as independent as
possible of network devices and topology. Two basic entities are
distinguished: the policy enforcement points (PEPs) and policy decision
points (PDPs). The PEPs typically reside on the managed devices. Their role
is to enforce the commands they receive in the form of configuration data
from the PDPs. The PDPs process the high-level policies along with other
data such as network state information and generate configuration data for
the PEPs.
The COPS protocol is designed
to communicate self-identifying policy-related information, exchanged
between the PDP and the PEP. In COPS, each PEP may support one or more
clients of different client types; different client types exist for the
different policing areas (security, QoS, admission control, accounting,
etc). COPS for Policy Provisioning (COPS-PR) is one of those client types.
COPS-PR uses special
structures called policy information bases (PIBs) that store policy
information at the PEPs and control the behavior of the devices. However,
the rigidity of its mechanisms constrains the intelligence that can be
pushed toward the managed devices.
This rigidity can be relaxed
by using meta-policies, rules that enforce the appropriate policies on the
devices. Meta-policies are stored and processed by the devices, independent
of their semantics, thus making the model more efficient, scalable,
distributed, and robust.
The additional functionality
is implemented through a PIB that stores and handles meta-policies. This
way, although the philosophy of the conveyed policing information is now
different, no modifications are required to the COPSPR protocol.
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Framework for Economical
MPLS Protection
The growth of MPLS as the
emerging choice for provisioning and managing core networks has placed
significant emphasis on MPLS based recovery mechanisms. MPLS based
protection can be categorized as Local protection or Global protection. In
case of local protection, the switch over to the backup path is performed by
the MPLS router (LSR) that is immediately upstream of the point of failure.
In case of global protection, this switch over is performed by a
pre-determined LSR known as Path Switch LSR (PSL). The PSL is usually
distant from the point of failure.
The present global protection
frameworks require extensive involvement of LSRs in the protection
framework. The LSRs are involved in failure propagation and maintenance of
information regarding upstream neighbors. This extensive involvement of the
LSRs in the protection frameworks may become a scalability issue
particularly in case of complex MPLS networks as a single failure may affect
many LSPs and PSLs. The restoration time in the present frameworks is
dependant on the length of the working path. This dependence leads to an
increase in the number of PSLs required for effective protection, which
thereby increases resource usage. The present frameworks also do not monitor
the PSL or the backup path for fault notification - a feature that is
important to ensure reliable protection frameworks.
We have proposed a framework
for economical global protection in MPLS networks. This framework is the
first framework that reduces the extensive involvement of intermediate LSRs
in the protection process. The framework provides resource-effective and
fast fault notification. The proposed framework also reduces the number of
PSLs required for effective path protection. The substantial reduction in
the involvement of intermediate LSRs and the reduction in the number of PSLs
provides an economical approach for protection in MPLS networks. We are also
able to monitor the PSLs, PMLs and the backup path in a cost-effective
manner.
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