Cisco Model D-PCG1000 PowerKEY CAS Gateway Release Notes
OL-31043-03
3
About This Software Version
Notes:
All [port rate] pairs are processed left to right.
The port settings are lost on a reboot or power cycle, unless set by the Autoexec
feature.
feature.
Manual CBR/VBR Mode Control
Netcrypt code replaces Null and PSI packets from the input with its own PSI and
ECM packets on the output. This is done to minimize the MPEG PCR jitter
introduced by the Netcrypt. This mode is called CBR mode because it is used with
CBR streams.
However, if there are insufficient input Null and PSI packets on any stream on a
given input port, the Netcrypt code automatically falls back to the Netcrypt 1.2.12
VBR mode for all streams on the entire port. This behavior, along with the periodic
attempts to transition back to CBR mode, can cause spikes in PCR jitter on the
Netcrypt output port.
Netcrypt release 1.3.9 provides manual control over the Netcrypt CBR/VBR mode.
The Netcrypt can run in CBR mode, VBR mode, or continue to use the automatic
fall-back behavior described previously. The feature is set using the command line
interface of the Netcrypt and can be stored in NVRAM using the e2prom_settings to
be preserved across Netcrypt reboots.
The available choices are:
ECM packets on the output. This is done to minimize the MPEG PCR jitter
introduced by the Netcrypt. This mode is called CBR mode because it is used with
CBR streams.
However, if there are insufficient input Null and PSI packets on any stream on a
given input port, the Netcrypt code automatically falls back to the Netcrypt 1.2.12
VBR mode for all streams on the entire port. This behavior, along with the periodic
attempts to transition back to CBR mode, can cause spikes in PCR jitter on the
Netcrypt output port.
Netcrypt release 1.3.9 provides manual control over the Netcrypt CBR/VBR mode.
The Netcrypt can run in CBR mode, VBR mode, or continue to use the automatic
fall-back behavior described previously. The feature is set using the command line
interface of the Netcrypt and can be stored in NVRAM using the e2prom_settings to
be preserved across Netcrypt reboots.
The available choices are:
Automatic (default): The Netcrypt attempts to run in CBR Mode, and
automatically reverts all streams on a port to VBR Mode if any stream on the
port does not meet input Null and PSI requirements. It also attempts to change
back to CBR Mode periodically. This is the same behavior as the previous
Netcrypt and is the default setting for this feature.
automatically reverts all streams on a port to VBR Mode if any stream on the
port does not meet input Null and PSI requirements. It also attempts to change
back to CBR Mode periodically. This is the same behavior as the previous
Netcrypt and is the default setting for this feature.
Manual CBR: The Netcrypt remains in CBR mode regardless of whether all of
the streams on each input port meet the Null and PSI requirements for this
mode. In the event that a particular stream does not meet the input Null and PSI
requirements, the Netcrypt continues to insert PSI and ECMs, but may be forced
to insert at at a rate less than the provisioned rates. This may have an effect on
PCR jitter in the output stream, but the effect should not be as abrupt as the
effect observed when toggling between CBR and VBR modes. To select this
behavior, log into the Netcrypt and enter a command on the CLI to select manual
CBR mode.
the streams on each input port meet the Null and PSI requirements for this
mode. In the event that a particular stream does not meet the input Null and PSI
requirements, the Netcrypt continues to insert PSI and ECMs, but may be forced
to insert at at a rate less than the provisioned rates. This may have an effect on
PCR jitter in the output stream, but the effect should not be as abrupt as the
effect observed when toggling between CBR and VBR modes. To select this
behavior, log into the Netcrypt and enter a command on the CLI to select manual
CBR mode.
Manual VBR: The Netcrypt drops input Null and PSI packets and inserts its own
output PSI and ECM packets at the provisioned rates. This behavior mimics the
Netcrypt 1.2.12 code’s handling of Nulls, PSI, and ECMs. To select this behavior,
log into the Netcrypt and enter a command on the CLI to select manual VBR
mode.
output PSI and ECM packets at the provisioned rates. This behavior mimics the
Netcrypt 1.2.12 code’s handling of Nulls, PSI, and ECMs. To select this behavior,
log into the Netcrypt and enter a command on the CLI to select manual VBR
mode.