Measurements from Data Plane
plays a significant role in improving video quality and therefore enhances the
QoE. Video monitoring implemented on
Cisco CRS Routers enable the network operator to measure
and track video transport performance on a per-flow basis in real time. In
contrast to the conventional traffic monitoring solutions, (where sampled flows
have to be sent to the control plane or additional hardware, such as dedicated
blade on the router), video monitoring on
Cisco CRS Router performs the monitoring operation on
the data plane itself. This enables video monitoring to analyze forwarded
packets in real time, to compute a metric that provides a measure of the
network performance impacting the quality of the video.
and Remote Access
measures packet loss and jitter at wire-speed, and stores collected information
on the router, in order that the network operator can access it through a user
interface. Furthermore, the performance metrics measured and stored on multiple
routers can be accessed through standard SNMP from a remote operation center.
These metrics provide a clear end-to-end picture of the video flow that can be
composed and analyzed.
Video monitoring on
Cisco CRS Routers serve both reactive and proactive
usage for service providers. It can be used to verify the quality of video
service, before scaling up the service coverage to new customers. Also, it is a
powerful tool for analysis and can be used to troubleshoot customer calls.
Network operators can configure video monitoring to raise an alarm for various
events such as variation in packet loss, jitter, flow rate, number of flows,
and so on. Such an alarm can be configured to get triggered at any possible
value or range.
Flow on Video
uses four pieces of packet header fields to distinguish a unique flow - source
IP address, destination IP address, source UDP port, and destination UDP port
(this implies protocol ID is always UDP).
supports not only the monitoring of flows with IPv4 multicast destination
address in the IP header, but also supports the monitoring of flows with
unicast destination addresses.
Flow Rate Types
and Protocol Layer
monitors CBR (constant bit rate) flows at the IP layer. In other words, video
monitoring can monitor CBR-encoded media streams (for example, MPEG-2)
encapsulated in UDP datagram, inside an IPv4 packet. Video monitoring allows
users to configure
expected packet rate at
IP layer, or bit rate at media layer (along with the number and size of media
supports both packet loss and jitter metrics that follow MDI (media delivery
index, RFC 4445) definition at the IP-UDP level. The MDI metrics are MLR (media
loss rate) and DF (delay factor). Video monitoring uses MRV (media rate
variation) which is an extension of MDI MLR; that is, MLR captures only loss,
while MRV captures both loss and excess. Video monitoring DF is the same as MDI
definition, where DF represents one nominal packet inter-arrival time in
addition to the monitored MDI jitter. Along with the two key metrics, Video
monitoring supports packet count, byte count, packet rate, bit rate, packet
size, TTL (Time to Live) field in IP header, number of flows, raised alarms,
and time stamp for various events.
The term MDI
jitter, is used to signify the correctness of DF metric measured by Video
monitoring. MDI jitter is measured by comparing the actual packet arrival time
against the nominal arrival reference, while simple inter-packet jitter is
measured by the time difference between two consecutive packet arrivals. The
former captures the performance of CBR flow more precisely than the latter.
Cisco CRS Router, only MRV is applicable.
Video monitoring on
Cisco CRS Router supports high availability at various
levels. It supports process OIR (online insertion and removable), line card
RP (route processor)
fail over, and router reload. Configuration is persistent for all high
availability scenarios. Monitored statistics data are preserved at process OIR
To activate video
monitoring, you must configure video monitoring service policy on an interface.
There are four types of interfaces to which you can attach the video monitoring
policy; these are main interface, subinterface, ethernet bundle interface, and
ethernet bundle subinterface. Video monitoring supports only layer 3 interfaces
and not layer 2 interfaces. Video monitoring can be configured only on the
input direction of the interface.
supports standard definition (SD) video traffic (mostly compressed) of up to
100 Mbps flow rate. For uncompressed video streams, flow rate of max 3 Gbps is
supports traditional CLI (command line interface) input for configuration that
follows MQC (modular QoS configuration) syntax. You can configure video
monitoring by configuring access control list (ACL), class map, and policy map;
it can be activated by attaching the service policy to an interface. In-place
policy modification is
In place policy
modification internally behaves like policy removal and attach. So, flows are
newly detected on the interface.
offers various show and clear commands for retrieving the monitored statistics.
Refer the Video Monitoring Commands on
Cisco CRS Routers module in the
Multicast Command Reference for Cisco CRS Routers for a detailed description of the
video monitoring commands.
You can configure
TCA (threshold crossing alert) as a part of the policy map to enable video
monitoring to generate syslog message for various conditions. You can also
retrieve standing alarms by using
show command or
through a SNMP pull. XML is supported by video monitoring.
Number of Class
Maps and Policy Maps
To use video monitoring,
you must configure class map and policy map that acts as a filter to determine
which flow to monitor on the data plane. Video monitoring supports a maximum of
512 class maps per policy-map, and a maximum of 1500 class maps per system. It
supports a maximum of 1500 policy maps on the system.
requires video PIE installation. Depending on the
RP type, the video pie name has
the following version: