Cisco Exam Questions

Drag the standard on the left to match correct description on the right.

DRAG DROP
Drag the standard on the left to match correct description on the right.

Answer:

Explanation:

802.1ah – PBB
802.1ad – QinQ
802.1ag – Connectivity fault management
802.1ah PBB
802.1ad QinQ
802.1ag Connectivity fault management
Benefits of IEEE 802.1ah standard
The benefits of IEEE 802.1ah provider backbone bridges are as follows:
• Increased service instance scalability
• MAC address scalability
IEEE 802.1ah Standard for Provider Backbone Bridging Overview
The IEEE 802.1ah Provider Backbone Bridge feature encapsulates or decapsulates end user
traffic on aBackbone Edge Bridge (BEB) at the edge of the Provider Backbone Bridged Network
(PBBN). ABackbone Core Bridge (BCB) based network provides internal transport of the IEEE
802.1ahencapsulated frames within the PBBN.
Overview of OAMThe advent of Ethernet as a metropolitan and wide-area networking technology
has accelerated the need for anew set of OAM protocols. Service provider networks are large and
complex with a wide user base, and theyoften involve different operators that must work together
to provide end-to-end services to enterprisecustomers. While enterprise end-customer demands

continue to increase, so do the requirements for serviceprovider Ethernet networks, particularly in
the areas of availability and mean time to repair (MTTR). EthernetOAM addresses these
challenges and more, thereby directly impacting the competitiveness of the serviceprovider.
Ethernet has been used as a LAN technology for many years, and enterprises have managed
thesenetworks effectively, primarily with the use of Internet protocols such as Simple Network
Management Protocol(SNMP), ICMP Echo (or IP Ping), IP Traceroute, andCisco Unidirectional
Link Detection Protocol (UDLD) andLayer 2 Traceroute (supported in Cisco Catalyst® OS and
some Cisco IOS® Software-based platforms). Inaddition to these troubleshooting protocols, Cisco
provides a wealth of other configuration, fault, networkmanagement, and performance
management tools. Cisco also supports MPLS OAM capabilities such asVirtual Circuit
Connectivity Verification (VCCV) and Label Switched Path (LSP) ping on the Carrier
Ethernetplatforms. To complement these OAM capabilities and to ensure that Ethernet can deliver
the requiredcustomer service-level agreements (SLAs), Cisco has developed comprehensive
Ethernet and IP SLA agents,along with an embedded event manager (EEM), and IPTV video
quality tools for automated measurement andtroubleshooting of Carrier Ethernet deployments.
Ethernet OAM addresses the following challenges:
• The existing protocols mentioned earlier will not work unless the Ethernet layer is operating
properly, making
Ethernet OAM a prerequisite.
• Many service providers do not want to overlay an IP infrastructure simply for management
andtroubleshooting of Layer 2 Ethernet services.
• The current management protocols lack the per-customer or per-service granularity that is
required tomanage the individual Layer 2 Ethernet services provided to enterprises.
• The existing protocols do not assist with provisioning of Ethernet services, which is particularly
difficult whenthe service provider and end customer must coordinate the configurations on their
respective Ethernetequipment.
Ethernet OAM is a broad topic, but this paper will focus on three main areas of Ethernet OAM that
are most inneed by service providers and are rapidly evolving in the standards bodies: Service
Layer OAM (IEEE 802.1agConnectivity Fault Management), Link Layer OAM (IEEE 802.3ah
OAM), and Ethernet Local Management
Interface (MEF-16 E-LMI). Each of these different OAM protocols has unique objectives and is
complementaryto the othersIEEE 802.1ad[note 1] is an Ethernet networking standard informally
known as IEEE 802.1QinQ and is anamendment to IEEE standard IEEE 802.1Q-1998. The
technique is also known as provider bridging,Stacked VLANs or simply QinQ or Q-in-Q.
The original 802.1Q specification allows a single VLAN header to be inserted into an Ethernet
frame. QinQallows multiple VLAN headers to be inserted into a single frame, an essential
capability for implementing MetroEthernet network topologies. Just as QinQ extends 802.1Q,
QinQ itself is extended by other Metro Ethernetprotocols.[specify]

In a multiple VLAN header context, out of convenience the term “VLAN tag” or just “tag” for short
is often usedin place of “802.1Q VLAN header”. QinQ allows multiple VLAN tags in anEthernet
frame; together these tagsconstitute a tag stack. When used in the context of an Ethernet frame, a
QinQ frame is a frame that has 2VLAN 802.1Q headers (double-tagged).
There is a mild confusion regarding the naming because the 802.1ad standard was grown out of
the802.1QinQ protocol (which was developed based the trademarked method 802.1Q, with capital
“Q” as adistinction instead of the 802.1q as the standardised protocol) which originally used
0x9100 as ethernet typeinstead of 0x88a8. While the network industry usually mix the naming the
proper, standardised name is802.1ad which sometimes gets appended by the other alternative
names mentioned above; the plain”802.1QinQ” name usually refers to the old standard which is
now considered obsolete