Architecture and operation
The Distributed Access Architecture (DAA) is a network implementation of intelligent Remote PHY Devices (RPDs) and Remote MACPHY Devices (RMDs) in a managed network. VUE supports RPDs/RMDs provisioning through the ACCP microservice. VUE also acts as a CCAP auxiliary core, using the GCP protocol to configure the video and SCTE 55-1 OOB channels and static pseudowires on all the RPDs/RMDs under its purview.
As shown in the figure below, VUE receives encrypted SPTSs or MPTSs over IP/UDP and UDP/RTP. It can multiplex the content creating MPTSs and inserting ancillary PID streams, in support of broadcast, SDV and VOD applications.
In a DAA deployment, the VUE forwards downstream video MPTSs and downstream SCTE 55-1 OOB streams to RPDs/RMDs, where each DEPI stream is uniquely identified with a multicast address and session ID. Each RPD/RMD receives a specific set of DEPI streams, each identified by a DEPI session ID. A common multicast address can be used for all broadcast MPTSs within a single ad zone. Narrowcast MPTSs use a different multicast address approach which is one multicast address for each narrowcast service group.
VUE supports the receipt of input transport streams that are carried within an RTP packet. VUE automatically detects and removes the RTP layer including support for variable size RTP headers and does not include the RTP header in the OTS. VUE identifies a count of the number of RTP packets sequence number errors since the input transport stream was mapped to an OTS and a count of the number of RTP packets sequence number errors detected on a mapped input transport stream within the last 5 second period.
Within a single ad zone, the set of output linear broadcast MPTSs is destined for all RPDs/RMDs within that ad zone and is sent on the same DEPI encapsulated IP multicast stream. All RPDs/RMDs within that ad zone must be configured by the VUE’s ACCP to receive that multicast IP group address for all broadcast QAM channels. Each QAM channel is provisioned with a different session ID to target a specific broadcast MPTS to a QAM channel. Each RPD/RMD receiving the same broadcast MPTSs must be configured with the identical set of broadcast QAM channels.
A set of output narrowcast (SDV, VOD) MPTSs intended for RPDs/RMDs belonging to the same narrowcast service group is sent. The set uses a different DEPI encapsulated IP multicast stream. All RPDs/RMDs within that narrowcast service group must be configured with this same multicast IP group address. Each narrowcast QAM channel within the service group must be configured identically across all RPDs/RMDs within the narrowcast service group (NSG).
When configuring a transport stream for DEPI, you must specify a unique combination of session ID and multicast address. This combination enables all RPDs/RMDs configured with the same QAM channels to use the same session IDs. This also allows assigning session IDs within a self-contained range to easily manage multicast session IDs across multiple CCAP cores.
VUE extracts upstream ARPD datagrams (carrying STB interactive/polling data) from UEPI-encapsulated data streams from the RPDs/RMDs, which are then forwarded to NC1500.
DAA configuration
The following sections cover DAA configuration for VUE: