Information Technology Reference
In-Depth Information
and low loss and delay between the camera source and the storage device to produce the
best video. We also see traffic from “unmanaged” sources from the Internet, such as video
from news sites, YouTube, and TV programming shows. Video traffic is more susceptible
to QoS issues than VoIP or data traffic, although end users are used to some intermediate
chop in video as long as the audio going with it does not skip. Table 14-6 shows the
packet-loss target for each traffic category.
Ta b l e 1 4 - 6
Data, Voice, and Video Sensitivities to Packet Loss
Key
To p i c
Traffic Type
Sensitivity to Multisecond Interruption
Packet-Loss Target
Data
To l e r a n t
1 % to 2 %
Vo i c e
Less tolerant
< 1 %
Video
Intolerant
< 0.05 %
The network designer should be aware that different video applications behave differently
and place different requirements on the network. Table 14-7 shows characteristics of video
media application models.
Ta b l e 1 4 -7
Video Media Application Models
To o l
Model
Flow Direction
Traffic Trends
Te l e P r e s e n c e
Many
to many
Client
←→
Client
4 Mbps to 12 Mbps for high-def video.
MCU
←→
Client
Desktop video
conferencing
Many
to many
Client
←→
Client
Collaboration across geographies.
Growing peer-to-peer model.
MCU
←→
Client
Video
surveillance
Many
to few
Source
→
Storage
Up to 3 Mbps to 4 Mbps per camera based
on video quality and frame rates.
Storage
→
Client
Source
→
Client
Desktop
streaming media
Few to
many
Storage
→
Client
Increase in application driving more
streams. Higher-quality video adds more
bandwidth.
Source
→
Client
