Specifications

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Cisco TV CDS 2.5 ISA Software Configuration Guide
OL-24788-01
Chapter 1 Product Overview
Content Delivery System Architecture
CDSM Redundancy
The Cisco TV CDS offers 1+1 redundancy for CDSMs. The primary CDSM, designated by a virtual IP
address on the management interface, is used as the representative of the CDSMs to the web browser and
northbound integrations, such as HTML API calls and SNMP calls.
All CDS servers keep track of a controller IP address in the .arroyorc file. With CDSM redundancy, both
management IP addresses are specified in the .arroyorc file on each CDS server, except the CDSM,
which only has the other CDSM IP address.
The statsd process is configured with a virtual IP address that can move from one CDSM to the other. If
the primary CDSM becomes unavailable, because of network, power, or other catastrophic problems, the
secondary CDSM takes over the virtual IP address and the administrator can connect to the secondary
CDSM within 15 seconds.
Login information is not shared between CDSMs. If the administrator is logged in and a failover occurs,
the administrator has to log in again to the other CDSM.
The CDS servers (Vault, Caching Node, Streamer, and ISV) participate in replication with both the
primary and secondary CDSM in the same manner as occurred without redundancy, including
synchronization of tables. However, the CDS servers can only retain up to one hour of reporting data, so
if a CDSM is down for over an hour, when the CDSM recovers, it only is able to get the last hour of
reporting data from each CDS server, which means the reporting data is not synchronized between the
primary and secondary CDSMs. Reporting data is archived in comma-separated value (CSV) files every
24 hours and these CSV files are deleted when they are older than 30 days.
Ethernet Link Resiliency
All Ethernet links used within the Cisco TV CDS architecture incorporate link failure detection with
automatic failover. This includes the interconnections between the Vault array and the Streamer array for
cache-fill, and the Ethernet links that carry the subscriber streams to the transport networks.
Scalability
The Cisco TV CDS has separated streaming and storage, which enables a cable operator to add storage
without affecting streaming counts, to add streaming without affecting storage, and in VVIs, to add
distribution nodes without directly affecting storage or streaming. This flexibility allows cable operators
to grow according to the needs of customers and to scale the system on an as-needed basis. For example,
if more storage is required, the cable operator adds a Vault server without taking the system offline, and
in Layer 2 networks the new device is automatically discovered within the architecture and the new
resources are automatically utilized by the system. If additional streaming is required, the content
provider either purchases more streaming licenses within the current servers, or a Streamer server is
added to the system without the need to take the system offline.