2. MEF Fundamental Components and Reference Models Flashcards
(208 cards)
Interface between two Operator MEN/CEN networks
ENNI
External Network-Network Interface
What MEF specification extends the basic reference model to define MEF services across multiple networks, with each MEN (CEN) independently owned and operated?
MEF 26.1
Service provider responsibility
from UNI to UNI
Operator responsibility
ENNI to UNI
In the General Reference Model, the independent networks are called what?
Operator MENs or Operator CENs
Interface between two Operator MEN/CENs
ENNI
External Network-to-Network Interface
True or False: In the General Reference Model, the Carrier Ethernet service is unchanged from the subscriber’s perspective.
True
In the General Reference Model how many Carrier Ethernet service providers are responsible for the service as a whole?
Only one
In the General Reference Model, the Carrier Ethernet service is implemented with how many EVCs connecting two or more UNIs?
Exactly one EVC (per Carrier Ethernet service)
True or False: In the general reference model, the basic reference model is sufficient to define the service from the subscriber’s perspective.
True
True or False: The General Reference Model adds details of implementation that are only important to the service provider and subcontracting operators.
True
True or False: A UNI, in general, can support more than one EVC.
True
Association of multiple EVCs to a single UNI
Service Multiplexing
Service multiplexing is a property of what?
A UNI
Is service multiplexing a property of the Carrier Ethernet service or EVC?
No.
Service multiplexing is a property of a UNI.
Key benefit of service multiplexing
Allows services to share UNIs, saving ports (physical connections) on subscriber and service provider edge equipment.
Ethernet frames are assigned to EVCs at UNIs based on what?
VLAN ID
Can an Ethernet frame be assigned to more than one EVC?
No.
An Ethernet frame transmitted across the UNI toward the SP or an Ethernet frame transmitted across the UNI toward the subscriber
Service Frame
True or False: All service frames are either:
1) untagged or
2) include an IEEE 802.1Q customer tag in the Ethernet header.
True
Includes 12 bits representing one of 4094 values that are used to identify the VLAN to which the Ethernet frame belongs.
VLAN Identifier (VID)
Two values in the VLAN ID (VID) space reserved for other uses and not available to identify subscriber VLANs.
0 and FFF
Two highest level C-Tag field groupings
- TPID (always 8100)
2. TCI (composed of PCP, CFI, and VID)
Length of VID field in TCI section of C-Tag
12 bits