MEF CECP Exam UPDATED
QUESTIONS AND CORRECT ANSWERS
SOAM (Service Operations Administration & Maintenance - CORRECT
ANSWER provides mechanisms for monitoring connectivity & performance for links,
services, etc. within the CEN. SOAM provides benefits to both the service provider and
subscriber.
How does SOAM benefit the Service Provider? - CORRECT ANSWER For the service
provider, SOAM provides the tools to monitor network and service connectivity and to locate
the source of connectivity faults
How does SOAM benefit the Subscriber? - CORRECT ANSWER For the service
subscriber, as well as the service provider, SOAM provides a standard way to measure
important metrics documented in the Service Level Agreement (SLA) such as availability and
delay
What are the 2 components of SOAM? - CORRECT ANSWER Fault management
(SOAM FM) and Performance Monitoring (SOAM PM)
Attributes of SOAM-PM - CORRECT ANSWER 1. Frame Delay (FD) - the time
required to transmit a Service Frame from ingress UNI to egress UNI
2. Inter-frame Delay Variation (IFDV) - the difference in delay of two Service Frames
belonging to the same CoS instance
3. Frame Loss Ratio (FLR) - a measure of the number of lost frames between ingress UNI
and egress UNI expressed as a percentage
4. Availability - a measure of the percentage of time that a service is useable
SOAM PM computations - CORRECT ANSWER - for E-LINE: measured and
computed separately in each direction (UNI A to UNI B and UNI B to UNI A)
- for E-LAN with N UNIs, there are N*(N-1) (ordered) UNI pairs.
- for ETREE: R root UNIs and L leaf UNIs, there are 2*R*L ordered UNI pairs between the
roots and leaves and an additional R*(R-1) ordered pairs between the roots.
, Ethernet Virtual Private Line or E-Line
Ethernet private line (EPL) and Ethernet virtual private line (EVPL) - CORRECT
ANSWER a service connecting two customer Ethernet ports over a WAN, all service
frames at the UNI are mapped to a single EVC (a.k.a. all-to-one bundling), high degree of
transparency.
-Unlike EPL, EVPL allows for service multiplexing (multiple EVCs or Ethernet services per
UNI)
-The other difference between the EVPL and EPL is the degree of transparency - while EPL
is highly transparent, filtering only the pause frames, EVPL is required to either peer or drop
most of the Layer 2 Control Protocols.
Ethernet Virtual Private LAN or E-LAN
(multi-point to multi-point) - CORRECT ANSWER a multi-point service connecting a
set of customer endpoints, giving the appearance to the customer of a bridged Ethernet
network connecting the sites
-VPLS
-EVP-LAN enables any-to-any communication between all customer locations associated
with the customer's EVC
-Service multiplexing is allowed at the UNI and EVPL and EVP-LAN service types may
share the same port. CE-VLAN IDs are maintained across the network.
Ethernet Virtual Private Tree or E-Tree
(point to multi-point) - CORRECT ANSWER a multi-point service connecting one or
more roots and a set of leaves, but preventing inter-leaf communication.
Ethernet over SDH/SONET
(Transport) - CORRECT ANSWER Point-to-point Ethernet links are carried over
SDH/SONET networks, making use of virtual concatenation and LCAS (Link Capacity
Adjustment Scheme) to create an appropriate size carrier bundle, of the Generic Framing
Procedure of SDH equipment, and takes advantage of the management and recovery features
of SDH to provide high availability and resilience to failures.
Ethernet over MPLS
QUESTIONS AND CORRECT ANSWERS
SOAM (Service Operations Administration & Maintenance - CORRECT
ANSWER provides mechanisms for monitoring connectivity & performance for links,
services, etc. within the CEN. SOAM provides benefits to both the service provider and
subscriber.
How does SOAM benefit the Service Provider? - CORRECT ANSWER For the service
provider, SOAM provides the tools to monitor network and service connectivity and to locate
the source of connectivity faults
How does SOAM benefit the Subscriber? - CORRECT ANSWER For the service
subscriber, as well as the service provider, SOAM provides a standard way to measure
important metrics documented in the Service Level Agreement (SLA) such as availability and
delay
What are the 2 components of SOAM? - CORRECT ANSWER Fault management
(SOAM FM) and Performance Monitoring (SOAM PM)
Attributes of SOAM-PM - CORRECT ANSWER 1. Frame Delay (FD) - the time
required to transmit a Service Frame from ingress UNI to egress UNI
2. Inter-frame Delay Variation (IFDV) - the difference in delay of two Service Frames
belonging to the same CoS instance
3. Frame Loss Ratio (FLR) - a measure of the number of lost frames between ingress UNI
and egress UNI expressed as a percentage
4. Availability - a measure of the percentage of time that a service is useable
SOAM PM computations - CORRECT ANSWER - for E-LINE: measured and
computed separately in each direction (UNI A to UNI B and UNI B to UNI A)
- for E-LAN with N UNIs, there are N*(N-1) (ordered) UNI pairs.
- for ETREE: R root UNIs and L leaf UNIs, there are 2*R*L ordered UNI pairs between the
roots and leaves and an additional R*(R-1) ordered pairs between the roots.
, Ethernet Virtual Private Line or E-Line
Ethernet private line (EPL) and Ethernet virtual private line (EVPL) - CORRECT
ANSWER a service connecting two customer Ethernet ports over a WAN, all service
frames at the UNI are mapped to a single EVC (a.k.a. all-to-one bundling), high degree of
transparency.
-Unlike EPL, EVPL allows for service multiplexing (multiple EVCs or Ethernet services per
UNI)
-The other difference between the EVPL and EPL is the degree of transparency - while EPL
is highly transparent, filtering only the pause frames, EVPL is required to either peer or drop
most of the Layer 2 Control Protocols.
Ethernet Virtual Private LAN or E-LAN
(multi-point to multi-point) - CORRECT ANSWER a multi-point service connecting a
set of customer endpoints, giving the appearance to the customer of a bridged Ethernet
network connecting the sites
-VPLS
-EVP-LAN enables any-to-any communication between all customer locations associated
with the customer's EVC
-Service multiplexing is allowed at the UNI and EVPL and EVP-LAN service types may
share the same port. CE-VLAN IDs are maintained across the network.
Ethernet Virtual Private Tree or E-Tree
(point to multi-point) - CORRECT ANSWER a multi-point service connecting one or
more roots and a set of leaves, but preventing inter-leaf communication.
Ethernet over SDH/SONET
(Transport) - CORRECT ANSWER Point-to-point Ethernet links are carried over
SDH/SONET networks, making use of virtual concatenation and LCAS (Link Capacity
Adjustment Scheme) to create an appropriate size carrier bundle, of the Generic Framing
Procedure of SDH equipment, and takes advantage of the management and recovery features
of SDH to provide high availability and resilience to failures.
Ethernet over MPLS
