Transcript The Network Management Problems

The Network Management
Problems
Tajudin Hassen
Over View





Linking together of Network Management with
continuing growth in traffic types and Volumes
presents main problem.
The Growth adds Multiple NMS which increases
operational expense
Growth of associated Management overhead.
Strong need to reduce the cost of ownership and
improve the return on investment (ROI).
Requirement of Automated flow-through actions
Requirement of Automated flowthrough actions
FCAPS areas included in the requirement
 Provisioning
 Detecting faults
 Checking and verifying performance
 Billing/accounting
 Initiating repairs or network upgrades
 Maintaining the network Inventory


Contents
•Bringing the Managed Data to the Code
•Scalability
•The Shortage of Development Skills for Creating
management systems
•The Shortage of Operational Skills for running Networks
Bringing the Managed Data to
the Code
Managed objects reside on many SNMP agent hosts
 Copies of managed objects reside on SNMP management
systems
 Changes in agent data may have to be regularly
reconciled with the management system copy
 The quality of an NMS is inversely proportional to the
gap between its picture of the network and the actual
state of the underlying network-the smaller the gap, the
better the NMS
 As managed NEs become more complex. An extra
burden is placed on the management system.

SCALABILITY
Today’s Network is Tomorrow’s NE
 Layer 2 VPN Scalability
 Virtual Circuit Status Monitoring
 MIB Scalability
 Other Enterprise Network Scalability
Issues
 Large Reading Trials
 Large NEs

Today’s Network is Tomorrow’s NE

A scalability problem occurs when an
increase in the number of instances of a
given managed object in the network
necessitates a compensating, proportional
resource increase inside the management
system.
Corporate Data
Enterprise Management Systems
 IT Service level Management (Helpdesk solution, SLAs)
 Enterprise Network, Applications and Systems
management
 Fault , Performance, Availability, Capacity Planning,
and Bandwidth Management
 Software deployment Management, inventory, metering,
distribution, remote desktop control, application healing,
and centralised controls e.t.c
Layer 2 VPN Scalability
A full mesh provides the necessary
connectivity for the VPN. Generally
referred to as the N squre problem.
 When the number of sites become very
large, virtual circuits required tends to
become unmanagable.

Virtual Circuit Status Monitoring

NMS attempts to read all table entries

MIB table entries becomes very large
MIB Scalability
Network operators and their users
increasingly demand
 more bandwidth,
 faster networks
 and bigger devices.

Other Enterprise Network Scalability
Issues
Scalability also affects the Enterprise
 Storage solutions
 Administration of firewalls
 Routers, such as access control lists and
static routes
 Security management
 Application management
 Large NEs

Expensive and Scares Development
Skill Sets

A Solutions Mindset

Distributed, Creative Problem Solving

Taking Ownership

Acquiring Domain Expertise
A Solutions Mindset

Reflects the move away from the purely
technological aspect of products to
embrace the way enterprises and service
providers look at overall solutions to
business problems.

FCAPS Software layers
Distributed, Creative Problem Solving
Software bugs
 NE bugs
 Performance bottlenecks
 Client applications crashing intermittently
 MIB table corruption
 SNMP agent exception

Taking Ownership
All NMS software developers should strive
to extend their portfolio of skills.
 Institutional memory relates to individual
developers with key knowledge of product
infrastructure

Acquiring Domain Expertise
Domain expertise represents a range of
detailed knowledge
 Knowledge might include

 Layer
2 and layer 3 traffic engineering
 Layer 2 and layer 3 QoS
 Network Management
 Convergence of legacy technologies into IP
 Backward and forward compatability
Linked Overviews

An ATM Linked Overview

An IP Linked Overview

Short Development Cycles

Minimizing Code Changes
Elements of NMS Development








NMS Development
Data Analysis
Upgrade Consideration
UML, Java, and Object-Oriented Development
Class Design for Major NMS Features
GUI Development
Middleware Using CORBA-Based Products
Insulating Applications from Low-Level Code
Expensive and Scarce operational
Skills

The growing complexity of networks is
pointing to increasingly scarce operational
skills.

Multiservice Switches
MPLS: Second Chunk











Explicit Route Objects
Resource Blocks
Tunnels and LSPs
In-segments and Out-segments
Cross-Connects
Routing Protocols
Signaling Protocols
Label Operations
MPLS Encapsulation
QoS and Traffic Engineering
QoS
PROBLEMS POSED BY ENTERPRISE
NETWORKING

CONNECTIVITY
 LOSS OF MANAGEMENT CONTROL
 ORGANIZATIONAL CHANGE
REQUIREMENTS
 HIDDEN COSTS OF CLIENT/SERVER
COMPUTING
 RELIABILITY & SECURITY
*
COSTS OF CLIENT/SERVER
SYSTEMS

OPERATIONS & SUPPORT
 APPLICATION DEVELOPMENT
 HARDWARE, SOFTWARE, INSTALLATION,
MAINTENANCE
 EDUCATION &
TRAINING
*
ENTERPRISE NETWORK

HARDWARE; SOFTWARE;
TELECOMMUNICATIONS, DATA
RESOURCES
 MORE COMPUTING POWER ON THE
DESKTOP
 NETWORK LINKING SMALLER
NETWORKS
*
ENTERPRISE NETWORK

HARDWARE; SOFTWARE;
TELECOMMUNICATIONS, DATA
RESOURCES
 MORE COMPUTING POWER ON THE
DESKTOP
 NETWORK LINKING SMALLER
NETWORKS
*
MPLS: Second Chunk
Explicit Route Objects
 Resource Blocks
 Tunnels and LSPs
 In-segments and Out-segments
 Cross-Connects
 Routing Protocols

Explicit Route Objects
ERO is a list of layer 3 address hops inside
an MPLS cloud
 Describes a list of MPLS nodes through
which a tunnel passes
 EROs are used by signaling protocols
(such as RSVP-TE) to create tunnels

Resource Blocks

Components of resource block include
 Maximum
reserved bandwidth
 Maximum traffic burst size
 Packet length
Tunnels and LSPs

MPLS-encapsulated packets enter the
tunnel exhibits 3 important characters
 Forwarding
is based on MPLS label rather
than ip header
 Resource usage is fixed, based on those
reserved
 Path taken by the traffic is constrained by the
path chosen
Cross-Connects
Point-to-Point
 Point-to-multipoint
 Multipoint-to-point

Routing Protocols

MPLS incorporates standard IP routing
protocols such as OSPF, IS-IS and BGP4
Router

Segments LANs into
distinct networks and
subnetworks; e.g. the
distinct red, green
and blue LANs with
distinct network
numbers.

Segments LANs into
broadcast domains
Ethernet switch
3rd floor
2nd floor
1st floor
router
Signaling Protocols

Signaled connections have
 Resources
reserved
 Labels distributed
 Paths selected by protocols such as RSVP_TE
or LDP
Label Operations
MPLS-labeled traffic forwarded based on
its encapsulation label value
 Current MPLS node uses Label2 encaps
 Operations executed against labels are

 Lookup
 SWAP
 POP
 PUSH
MPLS Encapsulation

The MPLS encapsulation specifies four
reserved label values
0-IPV4 explicit null that signals the receiving
node
1-Router alert that indicates to the receiving
node
2-IPV6 explicit null
3-Implicit null that signals the receiving node
QoS and Traffic Engineering
Providing specific chunks of bandwidth
(via MPLS LSPs) to the developers.
 Traffic engineering is set to become a
mandatory element of converged layer 3
enterprise networks.

QoS
Rating traffic as being equally important
 Rating VOIP traffic as being the most
important
 Three approaches for network services

 Best
effort
 Fine granularity QoS (IntServ)
 Coarse granularity QoS (DiffServ)
MPLS and Scalability
A network containing possibly tens or
hundreds of thousands of MPLS nodes.
 It is not practical to try to read or write an
object of this size using SNMP.
 Tunnel-change table
 Tunnel table

Summary
 Bringing managed data and code together
is one of the central foundation of
computing and network management
 Achieving union of data and code in a
scalable fashion is a problem that gets
more difficult as networks grow.
