●●● ●●●● ●●●●● ●●●● ●●●●● Network management example Mgmt Mgmt Mgmt Process Protocol a Pr ol Presentation Presentation Session Session Transport Trans port Network Network Data link Data link Physical Physical Managing Entity Managed device COMP4690, by Dr Xiaowen Chu, HKBU
COMP4690, by Dr Xiaowen Chu, HKBU Network management example Transport Presentation Data Link Session Network Physical Agent Process Mgmt Protocol Managed Device Presentation Transport Data Link Session Network Physical Mgmt Process Mgmt Protocol Managing Entity Mgmt App
●●● ●●●● ●●●●● ●●●● ●●●●● Network management example o To get value of MIB variable from mgmt agent 1. Mgmt app(part of Nms)on managing entity passes request to mgmt process 2. Mgmt process calls network mgmt protocol(e.g, SNMP 3. SNMP constructs Get-Request packet and sent it to the managed device through the network 4. Mgmt agent on managed device receives Get-Request 5. Agent process accesses requested value 6. SNMP constructs Get-Response packet and sent it to managing entity through the network 7. Mgmt process on managing entity receives response 8. Mgmt process passes data to mgmt app COMP4690, by Dr Xiaowen Chu, HKBU
COMP4690, by Dr Xiaowen Chu, HKBU Network management example ⚫ To get value of MIB variable from mgmt agent 1. Mgmt app (part of NMS) on managing entity passes request to mgmt process 2. Mgmt process calls network mgmt protocol (e.g., SNMP) 3. SNMP constructs Get-Request packet and sent it to the managed device through the network 4. Mgmt agent on managed device receives Get-Request 5. Agent process accesses requested value 6. SNMP constructs Get-Response packet and sent it to managing entity through the network 7. Mgmt process on managing entity receives response 8. Mgmt process passes data to mgmt app
●●● Network Management ●●●● ●●●●● ●●●● ●●●●● Overhead ●●●● o there is overhead in terms of o CPU cycles to generate and process information/packets May require dedicated Managing Entity o Bandwidth usage for sending request and recelving res ponses o a tradeoff between cost and benefit COMP4690, by Dr Xiaowen Chu, HKBU
COMP4690, by Dr Xiaowen Chu, HKBU Network Management Overhead ⚫ There is overhead in terms of ⚫ CPU cycles to generate and process information/packets ⚫ May require dedicated Managing Entity ⚫ Bandwidth usage for sending request and receiving responses ⚫ A tradeoff between cost and benefit
●●● Additional Network ●●●● ●●●●● ●●●● ●●●●● Management Capabilities ●●●● o For efficiency, multiple values can be constructed in a single get-Response packet e Can traverse Mib in logical order o Mgmt agent can send unsolicited mssages These are known as traps E.g., if a device goes down o Can request info from probes or remote monitors(RMoN Monitoring activity(traffic)on a network segment COMP4690, by Dr Xiaowen Chu, HKBU
COMP4690, by Dr Xiaowen Chu, HKBU Additional Network Management Capabilities ⚫ For efficiency, multiple values can be constructed in a single Get-Response packet ⚫ Can traverse MIB in logical order ⚫ Mgmt agent can send unsolicited mssages ⚫ These are known as traps ⚫ E.g., if a device goes down ⚫ Can request info from probes or remote monitors (RMON) ⚫ Monitoring activity (traffic) on a network segment
●●● Evolution of network ●●●● ●●●●● ●●●● ●●●●● Management ●●●● e In 1977 International Organization for Standards(so) began work on Open Systems Interconnection(oSi)reference model o Purpose was to "provide a common basis for the coordination of standards developments for the purpose of system interconnection, while allowing existing standards to be placed in perspective within the overall reference model OSI model published in 1984 (7 years COMP4690, by Dr Xiaowen Chu, HKBU
COMP4690, by Dr Xiaowen Chu, HKBU Evolution of Network Management ⚫ In 1977 International Organization for Standards (ISO) began work on Open Systems Interconnection (OSI) reference model ⚫ Purpose was to “provide a common basis for the coordination of standards developments for the purpose of system interconnection, while allowing existing standards to be placed in perspective within the overall Reference Model” ⚫ OSI model published in 1984 (7 years!)