Pass the Huawei HCIP-Access H35-211_V2.5 Questions and answers with ExamsMirror

Ethernet VLAN identifiers provide a practical limit of about 4K per broadcast domain. As user counts and services grow toward this boundary, Huawei recommends dual-layer VLAN (QinQ) to extend scale and maintain service isolation. Hence the planning threshold is ~4K.

Huawei anti-DoS on access boards performs periodic detection. Ports with consecutive detections of abnormal traffic are placed into a blacklist/quarantine state. The system then applies a random back-off interval before re-detecting; if no further anomalies are found, the port can be automatically removed from the blacklist.

In H.248, the MGC controls the MG by creating a Context (also called an empty connection) and then adding terminations to build point-to-point, multipoint, or conference topologies. During call setup the MGC typically creates an empty context first, then binds terminations as media is negotiated.

A is incorrect: contexts and terminations can be modified during the session.

B is incorrect as written (the association/context is released, not “used”).

C is incorrect: an MG limited to point-to-point cannot host three or more endpoints in one context.

In an H.248 (Megaco) control model, the MGC is the controller that issues provisioning/connection-control commands such as Add, Modify, Subtract, AuditValue, AuditCapabilities to the MG. The MG (Media Gateway) can initiate only specific messages toward the MGC to announce state changes or report detected events—namely ServiceChange (to indicate restart, failure, availability changes, etc.) and Notify (to report observed events collected per event descriptor). Therefore, among the listed options, the commands that the MG itself can send are ServiceChange and Notify.

In FTTB/C voice access with SIP, typical “off-hook but no tone/voice” faults are caused by signaling/control path or device status issues: abnormal MG (Media Gateway/H.248/SIP) interface state on the ONU, unreachable routing between ONU and IMS/softswitch, or a voice server outage. These directly prevent registration, call setup, or media negotiation, resulting in no tone or no audio.

Generic “upper-layer packet loss” on the OLT uplink is not a standard, deterministic root cause specifically for off-hook immediate sound failure; minor loss does not inherently suppress locally generated tones and is not listed as a primary cause in Huawei voice troubleshooting guidance.

In campus/access networks, IGMP (Internet Group Management Protocol) operates between hosts and the first-hop multicast router/querier on the local subnet. It controls host group membership (Join/Leave/Query/Report), allowing the device to learn which receivers are interested in specific multicast groups and to populate/maintain the local multicast forwarding state.

Huawei Anti-MAC-Spoofing binds the source MAC to the service flow/port to prevent address forgery. It is functionally exclusive with certain per-VLAN MAC check features (e.g., WMAC, SC, PPPoe-SMAC) to avoid conflicting validation logic. For IPoE users with fixed IP, operators typically configure static bindings/entries so that address and access policies remain consistent.

Option D is wrong: disabling Anti-MAC-Spoofing and removing fixed entries can affect service behavior; if forwarding is interrupted, that does impact user service—so the statement is self-contradictory and incorrect.

In SIP, each proxy/server that forwards a request prepends its own address to the top of the Via header list. Therefore, as A’s INVITE traverses C, then D, then E, server E adds its Via at the top last, followed by D, then C below it. The message that reaches user B shows the Via stack (top→bottom) as E → D → C, which corresponds to option C. RFC 3261 states that the server transport uses “the value of the top Via header field” to determine response routing, confirming that the most recent hop is at the top

Drag & Drop Answer (NGN layers → devices):

Network control layer → Softswitch

Service management layer → OSS system

Edge access layer → MA5800

Core switching layer → Core router

Why:

Softswitch handles call/session control ⇒ control layer.

OSS provides O&M/service management ⇒ service management layer.

MA5800 is an OLT/access device ⇒ edge access layer.

Core router provides backbone forwarding ⇒ core switching layer.