Test fragen Flashcards
Outline the main EDFA components
Optical isolator
Optical filter
Optical Pump
Doped fibre
The main advantages of SDH over PDH are?
- High transmission rates
- Simplified Add & Drop functionality
- Bandwidth for OAM&P purpose
- Pointers
- Network Management
- Interconnection
- Enhanced performance monitoring
- Future ready technology
What is a splitter (ADSL)?
A splitter is an electronic low pass filter that seperates the analog voice or ISDN signal from ADSL data frequencies
What is LDP?
- LDP is defined for the purpose of distributing labels in an MPLS environment.
- LDP is defined by the IETF in RFC 5036
What is the difference between WDM and FDM?
None, it is the same concept
Which one is more critical regarding xDSL?
NEXT is more critical for DSL systems than FEXT
In combination with which request is an ack-request allowed
INVITE
Link-state routing protocols are:
- Ospf
- Is-is
MPLS main components are:
- Ingress LSR
- Core LSR
- Engress LSR
Telekommunikation bezeichnet den informationsaustausch via räumlicher Distanz zum Benutzer (Früher Fernmeldewesen genannt) –> Heute:
Versteht man darunter den Datenaustausch moderner übertragungstechniken unter zuhilfenahme von Elektronik und Elektrotechnik
The basic idea of adsl is to divide the available frequency spectrum into three different channels
- Telephony services channel
- Upstream channel (16-640 kbit/s)
- Downstream channel (up to 9 Mbit/s).
There are types of amplifiers and regenerators
- 1R Amplificatino
- 2R Amplification and reshaping
- 3R Amplification, reshaping and retiming
Two types of crosstalk pose potential problems for DSL Systems
- Far end crosstalk
- Near end crosstalk
What are main sip tasks
- User location
- User availability
- User capabilities
- Session setup
- Session management
What are the benefits of MPLS VPN
Scalable VPNs
What are the main adsl components:
- ADSL modem at the customer premises
- Modem of the central office
- DSLAM (DSL access multiplexer)
- Splitter
What are the main benefits of optical networks:
- Fiber Capacity
- Restoration Capability
- Reduced Cost
- Wavelength Services
What are the main tasks of LDP
- Label Distribution and Management
- Discovery of neighbour LSRs
- Establishing and Maintaining LDP Sessions
- Monitoring and notification of errors
What are the tasks of POH?
- Alarming
- Error monitoring for VC
- Information about the content of VC
- Indication of path connectivity
- Maintenance functions
What is a B2BUA (functionality)
- He can also initiate a new session
- He can terminate an existing session
- He forwards SIP messages
- He provides a similar functionality as a proxy server
- He can also maintain media streams related to the session
What is a splitter (ADSL)
A splitter is an electronic low pass filter that seperates the analog voice or ISDN signal from ADSL data frequencies
What is behind the term php
It refers to the process whereby the outermost label of an MPLS tagged packet is removed by a LSR before the packet is passed to an adjacent egress LSR
What is true concerning labeling in MPLS
MPLS inserts a MPLS label between the 2nd and 3rd layer of each packet
What is optical attenuation
- impurities reducing the optical throughput of the fiber
- Hydroxyl radical (OH radical) causing strong attenuation
What is SDH
basis for a powerful backbone network
What is the basic idea of WDM single optical fibre
The sending of many different wavelengths down the same optical fibre
What is the difference between FDM and EC?
- The EC design is more flexible for changing upstream capacity!!
- The main disadvantage of EC is the requirement for echo cancellation logic!!
What is the purpose of the via header field
Routing of response
Main purpose of SOH is to provide:
- Service channels,
- error monitoring,
- Operational functions,
- Automatic protection switching
- Maintenance functions,
- Data communication channels
What is usually carried in the body of an INVITE request
- Session information
- Connection information
- Time zone
- Session description URI
- Bandwidth information
What kind of DSL do you know
Alles
Which kind of dispersion are there
Mode dispersion
Chromatische Dispersion / Materialdispersion)
Polarisierende Modendispersion
Which modulation technologies can be used for ADSL
- CAP
- QAM
- DTM
Which network elements are defined in SIP
alles
Which one is more critical regarding xDSL
NEXT is more critical for DSL systems than FEXT
Which optical components do you know?
alles
Which technology has been replaced by SDH
PDH
Why is ADSL asymmetrical
ADSL supports different data rates upstream and downstream
Was bedeutet Cell Breathing?
- Soft Handover zur z.B. nächsten UMTS Zelle
- Handover ins z.B. GSM Netz
- Verringerung des Versorgebereiches
- Reduktion der Datenrate
Die Verschiedenen Dimensionen des Multiplexverfahren betrifft:
Alles (code, zeit, raum, frequenz)
