H35-211_V2.5 Reviews Questions

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.

On Huawei OLTs, the standard QoS pipeline for upstream packets is: first perform traffic classification (identify flows), then marking (set CoS/DSCP as required), next apply traffic policing (rate-limit and color traffic), followed by congestion avoidance (AQM such as RED/WRED), and finally congestion management (queue scheduling/priority queuing). This ordered sequence ensures correct identification and marking before any rate enforcement, and that packets encounter AQM prior to scheduler-based dequeue.

Type C GPON protection uses two different OLTs (dual-home). With uplink status linkage configured, a failure of the active OLT itself or its uplink interface triggers a protection switchover to the standby OLT to maintain service continuity for ONUs homed through the protected ODN.

PITP (Port Identification Transparent Transmission) is used on access networks to carry a user’s physical access-location to the upper AAA/BRAS. It has two working forms: P-mode (PPPoE+)—injecting location identifiers into PPPoE discovery—and V-mode (Vendor-tag)—carrying vendor/location tags transparently upstream. The purpose is to let the upper server associate user credentials with access location and, by policy, restrict roaming. Options A, B, D, and E correctly describe these behaviors/terms. Option C is inaccurate as written: PITP itself does not “bind the authentication” or inherently “avoid theft/roaming”; it only delivers location info. Preventing credential theft/roaming is achieved by AAA/BRAS policy that uses the PITP-carried location, not by PITP alone.