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In the Name of the Most High . New Trends in Network Management. by Behzad Akbari Fall 2011. Need for new management technologies. Since late ’80s Networks have evolved Management needs have changed Management technologies have evolved
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In the Name of the Most High New Trends in Network Management by Behzad Akbari Fall 2011
Need for new management technologies • Since late ’80s • Networks have evolved • Management needs have changed • Management technologies have evolved • Mismatch in speed of evolution of networks and management requirements vis a vis management technology
Evolution of networks • In the mid-late ’80s • Devices simple, resource constrained • Capabilities were limited • Today • Increased functional complexity • Increased complexity in configuration • Increased intelligence and programmability of devices • Networks that provide a wide range of services • NGNs: Packet based networks for all services • Providing unfettered access for users to networks and to competing service providers for services of their choice
Source: ITU-T Workshop on NGN (jointly organized with IETF) Geneva, 1-2 May 2005
Source: ITU-T Workshop on NGN (jointly organized with IETF) Geneva, 1-2 May 2005
Changes in operator needs • Management of large backbone networks requires powerful configuration management • Move from device management approach to system management • Service centric view of network • VoIP (residential and business), multimedia streaming, IP TV, fast data connectivity, triple play • Increased speed of service delivery • Automation of business processes
Consequences for management • Rethinking management principles – integration of independent developments • Management support for delivering quality service • Changes resulting from “user” focus as opposed to “network” focus • Importance of developing standardized management software for easy maintenance and extensibility
Traditional approaches - Datacomm • SNMP based • Aim was to have simple small footprint protocol • Kept self contained and independent of other network services • Catered to fault, performance monitoring, simple configuration management • Soon after release, shortcomings were exposed
Key revisions in SNMP v2, v3 • Revised OBJECT definitions • counter64 type • Improved tables • unambiguous row selection • procedures for creation and deletion of rows • augmenting of tables • Notification definition • Manager-manager communication • SNMP v3 - Security
Drawbacks of SNMP • Inadequate information modeling – simple data structures and protocol operations • Object based rather than object oriented • No inheritance – so no information re-use • Inadequate primitive for bulk information retrieval • UDP transport restricts size of data that can be sent • Limited configuration management support • Low level semantics
Configuration management needs • Need to apply configuration changes to several network devices simultaneously • Download bulk configuration changes on many devices • Schedule configuration operations on devices at particular times • Roll back support • Co-ordinated activation of downloaded configurations
Overcoming SNMP shortcomings • Evolutionary efforts were made to address shortcomings • Improving SMI • Improving SNMP protocol • Enhancing configuration management capability
Evolutionary efforts - I • Internet Research Task Force (IRTF) and Network Management Research Group (NMRG) developed SMIng • Allows arbitrarily nested data structures • Facilitates re-usability of complex data structures • Extensible mechanisms • IETF was to develop a standards track for above in 2000 • Phase 1: requirements drawn up • Phase 2: 2 strong proposals emerged • Efforts to merge these failed, in 2003, group was wound up
Evolutionary efforts - II • Attempt to improve protocol shortcomings • Efforts to reduce overhead due to OID redundancy • Compression • Suppression of redundant OID fragments • Effect bulk transfer at MIB level instead of OID • Use of TCP as transport protocol • Did not meet with success because of industry reluctance to accept new technology
Evolutionary efforts - III • COPS PR for improving Configuration Management capability • Resource Allocation Protocol (RAP) –WG for policy based configuration and provisioning • Specification language: Structure of Policy Provisioning Information (SPPI) • TCP is transport protocol • Intends to make configuration changes based on PBMS
Selecting a management technology • Information model • Defines how the management information is represented, data structures, objects etc. Eg., SNMP/UDP/IP is management protocol and SMI for definition of data • Communication model • Defines protocol for exchange of management information, structure of PDU, protocol operations • Specifies how units of management information can be addressed • Organizational model • Actors, roles and principles of co-operation whether manager-agent, management by delegation, mobile agents, policy based etc.
Selecting a management technology • Efficiency and timeliness • Simplicity • Cost of development and maintenance • Maturity • Security • Overhead on managed equipment (CPU, memory footprint etc.) • Bandwidth overhead
Alternative management approaches • Web based management • embedded web server in device • Browser can connect to to the URL of the device and html pages with management information • Provides graphical displays of management information • Improved configuration facility, detailed device management • Drawbacks • More an EMS-like approach – no end to end view • High level management functions such as map based view, root cause analysis, trend analysis not supported
Web based & SNMP • Devices have an embedded web server as well as SNMP agent (dual interface) • Combines the advantages of both approaches • Manager agent paradigm • Efficient Fault and Performance monitoring capability offered by SNMP • Detailed configuration • Map based end-to-end view
MIF DataBase Desktop Management Interface Desktop Resident Management Applications Management Interface (MI) Service Layer (SL) API Component Interface (CI) Hardware/Software Components MIF: Management Information Format
Desktop Management Interface (DMI) • Industry standard generated by • - Desktop Management Task Force (DMTF) • Started in 1992 to manage PCs • Manages both hardware and software • Two standards • Management information format (MIF), similar to MIB • Program interface with two APIs
Component Interface DMI Service Layer Request/Confirms Indications MIF Access Management Interface MIF Set Synchronization and Flow Control MIF Install MIF DataBase Response/Confirms Events/Response Command Processing Event Processing MIF Processing
DMI MIB • MIF specified using ASN.1 syntax • Can be managed by an SNMP manager • DMTF task expanded to specify WBEM - Web-based enterprise management • DMTF • - Distributed Management Task Force
Web-Based Enterprise Management • WBEM based on Common Information Module • CIM is information-modeling framework intended to accommodate all protocols and frameworks • Object-oriented • Five components: • Web client • CIM object manager (CIMOM) • CIM schema • Management protocol • Managed objects with specific protocol
Microsoft WMI • WMI is Microsoft infrastructure to support WBEM CIM • WMI comprises management infrastructure, applications, and agents • CIMOM has plug-in management applications • COM/DCOM API specifies interface to CIMOM • CIM is the CIM schema • Object providers are management agents (e.g. SNMP agent)
New Management Technologies • TeleManagement Forum(TMF) Interfaces • MTNM • NML-EMS interface based on CORBA • MTOSI • OS-OS interface based on XML