OCAM8 Flashcards
What is the client signal?
Contains the traffic inputs into the optical network infrastructure. May be optical provider’s internal traffic, another carrier’s traffic or another operational entity
What can the client signal be?
1) A subtending electrical rate signal into a TDM-based NE
2) A lower bit rate optical SONET/SDH signal into higher line rate SONET/SDH NE
3) Any input traffic into a DWDM/CWDM system that operates outside the WDE system’s transport wavelength
What is an OC transport network line?
A network line is the connectivity between network elements. It may be single or multi wavelength and involves more than just the physical fibre: amplifiers, filters and protection schemes may also be included. Lines are responsible for the bulk movement of data across the OC transport network
What is OAM?
Operations, Administration and Maintenance define the process, protocols and applications for managing network equipment are resources. Day to day operations, troubleshooting and network upgrades are part of OAM
What is FCAPS?
Fault, Configuration, Accounting, Performance and Security is the framework that formalises OAM into standard responsibilities that must be enabled, supported and accounted for in an OC network. FCAPS is defined by the Internal Organisation for Standardisation. Is also be defined as Telecommunications Management Network (TMN) by the International Telecommunications Union (ITU)
What is an SLA?
Service Level Agreements are contractual agreement between a service provider and customer to outline the responsibilities and set exceptions and scope for the service provided. Financial penalties are often a component of an SLA.
Define Interexchange Carrier
An IXC is a telephone company that provides connections between local exchanges in different geographical areas
Define Access
A network that serves individuals or groups of homes and businesses
Define Local Area Network
A group of connected devices within the same building or group of buildings. Can be connected to another LAN or a WAN
Why did we evolve to DWDM networks?
DWDM allowed us to increase capacity without having o expand the existing fibre plant.
Compared to SONET/SDH what does DWDM not natively provide?
1) In band communication channels
2) OAM mechanism for alarm and notification
3) SLA supporting mechanism
4) Standardised OAM functionality
What does it mean to support carrier grade reliability?
Support:
1) Network availability, redundancy, resiliency, client signal protection
2) large capacity, standardised OAM, flexible client support, low latency
3) Flexible deployment options: linear, ring and mesh
What is Network Availability?
Based on the Mean Time Between Failures (MTBF) of YEs and the anticipated Mean Time to Repair (MTTR) after failure.
Uptime/total time
What is MTBF?
Vendor specific rating of NEs based in Telcordia standards SR-332 and MIL-HDBK-217
What is MTTR?
An operational rating that describes the duration of failures or the mean time to restore elements to normal operation
What is carrier grade availability?
Expressed as percentage over a year (8,760 hours). Carrier grade is at least 99.999% or 5.26 minutes available across the year.
Availability can be increased using link and NE redundancy
What are the types of redundancy?
1) Path - diverse physical fibre paths
2) NE redundancy - duplicated components
What NE components may be duplicated to offer redundancy?
1) Cards
2) Switch fabric
3) Power supplies
4) Cooling fans
5) Optics