Cisco Model D-PCG1000 PowerKEY CAS Gateway Installation Guide
Theory of Operation
4012215 Rev B
11
Unicast and Multicast Behavior
IP unicast and IP multicast addresses are supported at either or both of the NOBE
input and output for sessions and Transport Stream Routes (TSRs). Streams may be
received by the NOBE as unicast and output as multicast or vice versa. The NOBE
can support a total of 17 TSRs.
input and output for sessions and Transport Stream Routes (TSRs). Streams may be
received by the NOBE as unicast and output as multicast or vice versa. The NOBE
can support a total of 17 TSRs.
The current release of the NOBE supports Internet Group Management Protocol
version 2 and version 3 (IGMPv2 and IGMPv3).
version 2 and version 3 (IGMPv2 and IGMPv3).
NOBE Ports
As shown to the right, the NOBE
has four active GbE ports. There is
a MAC address assigned to each
port. Operators must assign an IP
address to any port they have
provisioned on the DNCS
Administrative Console. In a Layer
3 (routed) network, operators must
provide a gateway IP address for
any port they provision on the
DNCS Administrative Console.
has four active GbE ports. There is
a MAC address assigned to each
port. Operators must assign an IP
address to any port they have
provisioned on the DNCS
Administrative Console. In a Layer
3 (routed) network, operators must
provide a gateway IP address for
any port they provision on the
DNCS Administrative Console.
The first four ports of NOBE are active GbE ports. These
ports behave independently. Content coming in on any
one port is processed and leaves using the same port.
Routing between ports is not supported.
Note: GbE ports 5 to 8 are not active.
GbE Headroom
In designing a content routing and transport network, operators should provide
some amount of headroom at all GbE ports. Bursty traffic can cause the
instantaneous Ethernet frame arrival rate to exceed 1 Gb/s, even when the average
rate is well below this. When this occurs, the switch or router will buffer some of the
frames up to the memory capacity of the dedicated or shared buffer on the
switch/router. When this capacity is exceeded, the switch/router discards the
frames. As a result, it is possible to experience video glitching and macroblocking
even though the switch/router and NOBE all can handle the full GbE rate. The
required amount of headroom can vary between 0 to 40 percent of the port capacity,
or even more, depending on the burstiness of the source or VOD server.
some amount of headroom at all GbE ports. Bursty traffic can cause the
instantaneous Ethernet frame arrival rate to exceed 1 Gb/s, even when the average
rate is well below this. When this occurs, the switch or router will buffer some of the
frames up to the memory capacity of the dedicated or shared buffer on the
switch/router. When this capacity is exceeded, the switch/router discards the
frames. As a result, it is possible to experience video glitching and macroblocking
even though the switch/router and NOBE all can handle the full GbE rate. The
required amount of headroom can vary between 0 to 40 percent of the port capacity,
or even more, depending on the burstiness of the source or VOD server.