Eliminate Risk of Failure with Ericsson ECP-206 Exam Dumps

In an Ethernet frame carrying a VLAN tag, the VLAN tag appears before the type field. A VLAN tag is a 4-byte field that is inserted into an Ethernet frame to indicate the VLAN membership and priority of the frame. The VLAN tag consists of two subfields: the tag protocol identifier (TPID) and the tag control information (TCI). The TPID subfield is a 16-bit field that identifies the frame as an IEEE 802.1Q-tagged frame, with a value of 0x8100. The TCI subfield is a 16-bit field that contains the priority code point (PCP), the drop eligible indicator (DEI), and the VLAN identifier (VID). The VLAN tag appears between the source MAC address and the type fields of the original frame, shifting the type field by four bytes. The type field indicates the type of the payload, such as IP or ARP .

A network operator who wants to make sure voice data is prioritized should assign it to Ethernet traffic class 6. Ethernet traffic class is a term used to refer to the priority code point (PCP) field in the VLAN header of an Ethernet frame. The PCP field is a 3-bit field that can encode up to eight different priority levels, ranging from 0 (lowest) to 7 (highest). The PCP values can be mapped to different types of traffic according to their QoS requirements. The recommended mapping is as follows :

PCP 0: Best effort (default)

PCP 1: Background

PCP 2: Spare

PCP 3: Excellent effort

PCP 4: Controlled load

PCP 5: Video

PCP 6: Voice

PCP 7: Network control

Voice data is a type of real-time traffic that requires the highest priority and lowest delay in the network. Therefore, it should be assigned to PCP 6, which corresponds to Ethernet traffic class 6 .

The statement that accurately defines an Autonomous System (AS) is that an AS is a set of routers under a single administration, using an interior gateway protocol and common metrics to route packets within the AS. An AS is a logical grouping of networks that share a common routing policy and operate under a single administrative authority. An AS can be a single network or a collection of networks that are interconnected by routers. An AS uses an interior gateway protocol (IGP), such as OSPF or IS-IS, to exchange routing information within the AS. An IGP uses common metrics, such as hop count or bandwidth, to determine the best path to each destination within the AS. An AS also has a unique number assigned by IANA, called an AS number (ASN), which identifies the AS in interdomain routing .

Referring to the exhibit, the service provider should implement L3VPN using the MP-BGP protocol to connect the sites for two customers (indicated in red and green in the exhibit). L3VPN is a type of VPN that uses MPLS to provide IP connectivity between customer sites across a service provider network. L3VPN allows customers to use overlapping or identical IP addresses without causing conflicts or requiring NAT. L3VPN uses MP-BGP to exchange VPN routes between PE routers, which are routers that connect customer networks to the service provider network. MP-BGP is an extension of BGP that can carry multiple address families, such as VPNv4 or VPNv6, along with additional attributes, such as route distinguisher (RD) and route target (RT).RD is used to make customer routes unique within the service provider network, while RT is used to control which routes are imported or exported between different VPNs3.

The correct order of DiffServ priority (highest to lowest) for the DiffServ classes: Default Forwarding (DF), Network Control (NC), Assured Forwarding (AF), and Expedited Forwarding (EF) is EF, NC, AF, DF. DiffServ is a QoS model that classifies and prioritizes traffic into different service classes based on the DSCP field in the IP header. The DSCP field is a 6-bit field that can encode up to 64 different per-hop behaviors (PHBs). The DiffServ classes are predefined groups of PHBs that have similar characteristics and requirements. The four main DiffServ classes are:

EF: This class provides the highest priority and lowest delay for real-time applications such as voice and video.The DSCP value for EF is 101110 or 46 in decimal12.

NC: This class provides the second highest priority and low delay for network control traffic such as routing protocols and network management.The DSCP value for NC is 110000 or 48 in decimal12.

AF: This class provides four levels of assured forwarding with different drop probabilities for each level. AF is suitable for applications that require guaranteed bandwidth and delivery assurance, such as web browsing and email.The DSCP values for AF range from 001010 to 011110 or 10 to 46 in decimal12.

DF: This class provides the lowest priority and best-effort service for applications that can tolerate packet loss and delay, such as file transfer and backup.The DSCP value for DF is 000000 or 0 in decimal12.