Jeremy's IT Lab CCNA QoS (Part 1) Day 46

Cisco ILP offers [...] watts of power.

7

Cisco ILP uses [...] powered wire pairs.

2

Electronic devices use [AC/DC] power.

DC

Configure the voice VLAN:

SW1(config-if)# [...]

switchport voice vlan vlan-number

PoE (Type 1) is IEEE [...]

802.3af

PoE (Type 1) offers [...] watts of power.

15

PoE (Type 1) uses [...] powered wire pairs.

2

PoE+ (Type 2) is IEEE [...]

802.3at

PoE+ (Type 2) offers [...] watts of power.

30

PoE+ (Type 2) uses [...] powered wire pairs.

2

PoE: [...] can be configured to prevent a PD from taking too much power.

Power policing

PoE: What does PD stand for?

Powered Device

PoE: What does PSE stand for?

Power Sourcing Equipment

Power policing: Configure the switch to disable the interface and generate a Syslog message if the PD draws too much power:

SW1(config-if)# [...]

power inline police

or

power inline police action errdisable

Power policing: Configure the switch to restart the interface and generate a Syslog message if the PD draws too much power:

SW1(config-if)# [...]

power inline police action log

QoS: [...] is the amount of time it takes traffic to go from source to destination.

Delay (=one-way delay)

(Two-way delay measures both ways)

QoS: [...] is the percentage of packets that do not reach their destination.

Loss

QoS: [...] is the variation in one-way delay between packets sent by the same application.

Jitter

QoS: [...] refers to the overall capacity of a link.

Bandwidth

QoS: By default, queued messages will be forward in a [...] manner.

FIFO

QoS: What does RED stand for?

Random Early Detection

QoS: What does WRED stand for?

Weighted Random Early Detection

QoS: What features drop random packets when traffic queues pass a certain threshold?

RED / WRED

Tail drop is harmful because it can lead to [...].

TCP global synchronization

UPoE (Type 3) is IEEE [...]

802.3bt

UPoE (Type 3) offers [...] watts of power.

60

UPoE (Type 3) uses [...] powered wire pairs.

4

UPoE+ (Type 4) is IEEE [...]

802.3bt

UPoE+ (Type 4) offers [...] watts of power.

100

UPoE+ (Type 4) uses [...] powered wire pairs.

4

What does Cisco ILP stand for?

Cisco Inline Power

What does FIFO stand for?

First In First Out

What does PoE stand for?

Power over Ethernet

What does POTS stand for?

Plain Old Telephone Service

What does PSTN stand for?

Public Switched Telephone Network

What does VoIP stand for?

Voice over IP

What is considered acceptable jitter for interactive audio traffic?

30 ms or less

What is considered acceptable loss for interactive audio traffic?

1% or less

What is considered acceptable one-way delay for interactive audio traffic?

150 ms or less

When packets are dropped due to a full queue, it is called [...].

tail drop

When the switchport voice vlan command is applied to an interface, which traffic will be tagged? Traffic from the PC or from the IP phone?

Traffic from the IP phone

(traffic from the PC will be untagged as usual for an access port)