Title: Network Management,
1- Network Management,
- Management Information Base (MIB)s
- and
- Multiprotocol Label Switching (MPLS)
- Principles, Design and Implementation
- Stephen B. Morris
- Chapter 6
- Network Management
- Software Components
- By
- Stanley Zurita Mohamed Abdallatif
2NETWORK MANAGEMENTSOFTWARE COMPONENTS
- There are many possible solutions to NMS
development - this chapter describes one possible
structure - Server-side components
- Network-receiving asynchronous
- Network-receiving synchronous
- Network-sending
- Database access
- Client-side components
- Middleware components
- Data presentation, such as XML
- Northbound interface
3Figure 1
4Typical servers provide the following functions.
- Servicing client user requests
- Issuing provisioning operations, such as writing
to agent MIBS(inserting table entries,
updating/deleting existing objects) - Special-purpose listening operations, such as
monitoring LSP operational state - Providing generic service, such as scheduling
- Providing specific service, such as NE, firmware
and configuration data-base back-up, restore, and
distribution - Handling incoming notifications from network
5- Database forms the glue that ties together the
major component - Clients
- Middleware
- Server
- NEs
6Thin client tend not to use database directly and
instead rely on the server to manage the database
- Recording client-initiated operations, such as
creating FR or ATM virtual circuits - Storing the detail of scheduled operations and
associated result
7- Thin client can be based on standard Web browser,
there can be many such clients, and where to
carry out bulk of the processing is an important
design decision. If the principal requirement for
client software is fast execution, then as much
as possible of the MIB and database access should
be carried out by the client rather than the MIB.
If the client software is required to be simple
and intuitive to use, then it should be designed
to be as generic as possible. Generic software
hides complex network data as much as possible
and presents simple visual object proving default
values where appropriate.
8This involves setting the MIB object values for
- Bit rate
- Parity
- Number of data bits
- Number of start bits
- Number of stop bits, and so on
9Fault Server
- The purpose of the Fault Server is to process NE
notification. It faces into the network and seeks
to maintain parity between the NMS picture of
network faults and the real situation in the
network. A Fault Server will generally provide
the following features - Listening for notifications
- Determining the underlying problem (root-cause
analysis) - Updating persistent repositories and any GUI
visual indicators
10Fault Server Database Tables
- Node ID(the Key)
- Description A text string embedded in the
notification explaining the fault - Origin The originating NE(processor, card,
fabric,etc..) for the fault - Status active, cleared, acknowledged( the user
knows about the fault but has not cleared it) - Color Red for active, blue for acknowledged,
green for clear
11Topology Update
- CORBA
- J2EE
- JAVA RMI
- RPC
- Database update
12Configuration Server
- The purpose of the configuration server is to
execute client-initiated directives made against
NEs. Like the Fault Server, it also faces into
the network but operates in less open-ended way
because it is not required to process
asynchronous NE-originated notifications.
13Lets assume that a client user creates an LSP
(label Switched Path) there are three types
- Signaled
- Best-effort
- Unidirectional
Origin Destination Signaling Protocol Required QoS Explict Route Object
LER1 LER2 LDP BEST EFFORT NONE
14(No Transcript)
15Secure User
- Security Setting
- No authentication and no encryption
- Authentication and no encryption
- Authentication and encryption
16Trace Files
- Software bugs
- SNMP timeouts, such as a third-party NE that has
a slightly slow (or heavily loaded) agent - Bad values in MIB operations, such as trying to
write an illegal value to a MIB object
17Generic Connection Table Update
- ATM virtual connection (PVX and SPVX0
- MPLS LSP( signaled and unsignaled)
- FR cross connections into an MPLS core
- SONET path
18Topology Update
- Change the administrative status of a connection
from up to down - Creating a new LSP
- Deleting an existing LSP
19Configuration Server Database Tables
- Generic connection table these contain data
relevant to all connection types Keyes by index
value or origination/ destination node IDs - Technology-specific connection tables These
contain data relevant to specific connection
types, such as ATM PVX and LSPs - Operations log tables These are for recording
configuration change - Operations result log tables These are recording
all configuration change results
20ACCOUNTING SERVER
- Accounting and performance software share a
number of similarities. The Accounting Server
faces into the network and receives data record
periodically generated by NEs. Often, the data
records are emitted based on a preconfigured
time. It is also possible for an accounting
Server to poll MIBs for specific data ultimately,
accounting data is concerned with billing users
for network resources consumption.
21Mediation
- Mediation is the process of analyzing the raw
data generated by NEs to produce standard format
billing details for downstream use by third-party
applications (from organizations such as
ACECOMM). It is not necessary to use standard
formats if the billing application is
proprietary. However, standard format have the
merit of allowing different third-party
application to be swapped in as required.
22Aggregation
- This is the process by which separate CDRs are
combined. An example is an ATM PVC that spans a
number of NEs - Number of IP packets transported (if the circuit
is an LSP) - Number of cells transported per second (if the
circuit is an ATM connection) - Number of cells dropped due to excessive input
traffic - Average bandwidth used by the cell traffic
- Number of SLA contract violations
23Correlation
- Correlation is the process of combining multiple
units of aggregated data with the details of the
ultimate bill recipient, that is, one customer. - Number of cells sent to or received from the SP
network - Bandwidth used in transporting the data across
the ATM link
24Reports
- Utilization of objects, such as LSPs
- The average and peak numbers of IP packets
transported by the LEP - The bandwidth consumed
25Performance Server
- The purpose of the Performance Server is to
analyze network data in order to - Determine if problems exist prior to their
affecting services - Maximize network utilization
- Pre-empt the occurrence of congestion
- Demonstrate compliance with agreed SLAs
- Indicate when extra network investment is
needed(capacity planning)
26SLA Alert
- It is very important for enterprises to avoid
violating SLA terms because there may be
financial penalties.SLA alert can be issued based
on ongoing analysis of trends in an effort to
pre-empt violations before they actually occur.
27Source IP address 10.81.1.45
Source Port 444
Destination IP address 10.81.2.89
Destination Port 445
Link Bandwidth 10Mbps
Interpacket Delay 1ms
Ordered Delivery Yes
Packet Loss 0.0001
Jitter No
Round Trip Delay 30ms
28- This SLA indicates that IP traffic from
10.81.1.45 port 444 will land in the SP network
on a 10Mbps link destined for 10.81.2.89 port
445. The interpacket arrival time is specified to
be no more than 1 millisecond with no packet
arriving out of order. A tunneling technology
such as MPLS or L2TP could be employed to achieve
the latter.
29Topology Update
- When congestion is imminent on a given link
- When a virtual circuit is being presented with
excessive traffic-it may be necessary to add
extra bandwidth to the circuit
30Performance Server Database Tables
- Nodes
- Interface
- Links
- Virtual connections
- Each table has separate columns for relevant
performance - Number of incoming and outing packets, cells, and
frames - Bandwidth in use
- SLA status
31Security Server
- If there is one area of network management that
has moved to the top of the operators, agenda,
it is security, - Access application SNMP, telnet, secure shell,
Web, console( serial port) - Authentication Password, community string,
Kerberos, user-based security Remote Access
Dial-In User Service (RADIUS) - Privilege level Super user, Read-only, and User
- Permitted views Specific objects and sources
32Access Applications
- Limited or no logging apart from that provided by
the NE or CLI - Fairly open access to sensitive NE data
- It may be error-prone, and help facilities may be
quite limited
33Some popular access applications are
- SNMP
- Telnet
- Secure Shell
- Web
34Authentication Privilege Level
- Read-only
- User-level
- Superuser
- Read-only access allow only MIB get user-level
allows gets and some sets superusers can get and
set all appropriate
35Permitted Views
- Access control list
- Permitted object views
- An access control list contain the source IP
addresses allowed to connect to an NE. Permitted
object views specify a subset of MIB object
accessible to a given NMS user
36Discovery Server exist to keep up with the detail
of the deployed NEs Discovery keep track of
- Nodes
- Interface and underlying stacks
- Links
- Virtual connection
- Cross connections between different technologies
- Routing protocols
- Routing Tables
- Signaling protocols
- ICMP
- SNMP
- Standard and proprietary signaling protocols
37NE Software Distribution
- FTP/TFTP
- Proprietary download mechanisms
- Using an NMS
38Distributing NE in step
- Preparing the NE for a new firmware load
- Rerouting traffic around any nodes to which
downloads are pending - Initiating the transfer
- Handling rollback if the transfer fails
- Verifying the transfer succeeded
- Starting up the new NE software
39Preparing the NE may involve
- Bring the NE into a quiescent state
- Closing down existing connections
- Ensuring that no resource are in use on the NE
- Determining the available FLASH and RAM free
space - Taking a copy of the existing firmware
40NE Configuration Database Backup and Restore
- Some reason for backing up
- New firmware build may upgrade the configuration,
making rollback difficult - Disaster recovery
- Creating Mirror network
- Using a given configuration as a template
41NMS should handle the complexities of
- Knowing where the appropriate configuration data
flies are located - Handling the transfer via FTP, TFTP, and so on
- Restart the NEs or reloading the data files
- Informing the operator when the operation is
complete - Rerouting traffic around the nodes being restored
42Middleware
- Middleware is the part of an NMs that allow
communication between the clients and servers,
There is a broad range of software technology
choices for achieving this, including
RPC,JAVA,COBRA, J2EE, and Microsoft.Net
43SUMMARY
- The implementation of NMS software can take the
form of sever .These are high perform software
objects that can support interaction with both
external clients and NEs, It is essential that
server are resilient and designed so that they
are unlikely to fail except in exceptional
circumstances. They form the intermediate layer
through which end users can securely communicate
with NEs.
44- The need for generic software components is
growing with the increasing deployment of dense,
multiservice NEs Generic software attempts to
abstract complex NE data as much as possible and
present simple GUIs applicable across a broad
range of devices. - On the client side, GUI views are often depicted
as network topologies accompanied by fault
listings, It is a major challenge for the NMS
software to keep these views synchronized with
the network. It is always hard to escape form
legacy NEs, and for this reason it is often
necessary for server components to be SNMP
multilingual, that is able to use any of
SNMPv1/2c/3.