TechNotes & Glossary
In order to succeed and continue to see returns on their investments, video service providers (VSPs) need to deliver an overall branded experience to the customer with more perceived value than...
Loudness, Monitoring and CALM Act Compliance
Presentation given by Jim Welch at the SCTE Cable-Tec Expo 2011 in Atlanta, GA.
This presentation provides some key background information about the formation of the CALM Act and the basis...
New intelligent quality assurance technologies are needed to monitor Adaptive Streaming, which is used to deliver Over-The-Top (OTT) video. With patented and patent-pending technologies, IneoQuest...
Program availability is a key performance indicator for the quality of video distribution as described in the recently published SCTE 168-6 2010 'Recommended Practice for Monitoring Multimedia...
MDI - The Media Delivery Index
MPEG video transport streams undergo time distortions known as jitter when being transported by packet switched networks such as Ethernet. Identifying and measuring jitter and packet loss in such...
- ASI or DVB-ASI: Asynchronous Serial Interface
- The physical interface that is designed to transport video transport streams serially over coax cable at up to 270Mb/s. DVB is a family of European digital video standards.
- IP Multicast: Internet Protocol Multicast
- IP Multicast delivers source traffic to a group of receivers without adding any additional burden on the source or the receivers while using the least network bandwidth of any competing technology. Multicast packets are replicated in the network resulting in the most efficient delivery of data to multiple receivers’ possible. All alternatives require the source to send more than one copy of the data.
- IGMP: Internet Group Management Protocol (ver 1,2)
- (as per RFCs 1112/2236) IGMP is used to dynamically register individual hosts in a multicast group on a particular LAN. Hosts identify group memberships by sending IGMP messages to their local multicast router. Under IGMP, routers listen to IGMP messages and periodically send out queries to discover which groups are active or inactive on a particular subnet.
- IP-SBR: IP Stream Bitrate
- The IP Stream Bitrate is the measured data (payload) per second of a given media over IP stream. The type of the payload is not considered just the amount of payload in bytes measured.
- MDI-DF: Delay Factor
- Delay Factor is a metric which characterizes IP Packet cumulative jitter and delay. The DF is the amount of buffer, in milliseconds, that would be required to subtract IP packet arrival deviations from the rate determined by the media payload.
- MDI-MLR: Media Loss Rate
- Media Loss Rate is the number of media packets lost per second.
- MDI-MLT: Media Loss Total
- Media Loss Total is the total number of media packets lost for a given inspection period.
- MDI-MLT-15: Media Loss Total-15
- Media Loss Total is the total number of media packets lost for the current 15-minute inspection period.
- MDI-MLT-24: Media Loss Total-24
- Media Loss Total is the total number of media packets lost for the previous 24 hour inspection period. It provides a history of the last 96 15-minute inspection periods.
- MDI-VB: Virtual Buffer
- Virtual Buffer is the same as DF expressed in bytes for a given media stream rate. The VB is the amount of buffer, in bytes, that would be required to subtract IP packet arrival deviations from the rate determined by the media payload.
- MLS: Media Loss Seconds
- Media Loss Seconds is the total number of seconds that saw a loss of media packets from the time the stream was recognized.
- MLS-15: Media Loss Seconds-15
- Media Loss Seconds is the total number of seconds that saw a loss of media packets for the current 15-minute inspection period.
- MLS-24: Media Loss Seconds-24
- Media Loss Seconds is the total number of seconds that saw a loss of media packets within the previous 24 hour inspection period.
- Multicast IP Address
- (as per RFC3171) IP multicast address are defined as IP addresses within the range 220.127.116.11 and 18.104.22.168. IP multicast addresses within 22.214.171.124 and 126.96.36.199 are reserved for network protocols. A multicast HOST will generate traffic with an IP destination address within the defined multicast range. Multicast RECEIVERS that are interested in receiving data flowing to a particular group must join the group using the IGMP protocol.
- Nominal Bitrate
- The Nominal bitrate is the media bitrate calculated when the transport stream is initially detected.
- PAT : Program Association Table
- >A Program Association Table is a specific PID that every transport stream is required to contain. It provides the correspondence the program numbers and the PIDs defined in the PMT. The PAT may be partitioned into 255 sections before it is mapped to a transport stream to minimize loss.
- PCR: Program Clock Reference
- The program clock reference (PCR) is transmitted within a video transport stream as a time reference. A sufficiently accurate and correctly received PCR is a precondition for correct data display in the receiver.
- PID : Packet Identifier
- A Packet Identifier is a unique 13-bit identifier located within the first 4-byte prefix of a transport stream used to identify components of the transport stream, such as PES, program tables, PCR for each program, etc. Certain PIDs are predefined, such as :
8191 = stuffing PID
8187 = PSIP PID (Program and System Information Protocol)
- PMT : Program Map Table
- A specific PID within a transport stream which provides the mapping between a program number and the program elements it is comprised of. It contains a minimum of a program number, PCR PID, stream types and program element PIDs.
- PSIP : Program and System Information Protocol
- A protocol defined by the ATSC digital television standard for carrying data about each channel within the transport stream; such as content ratings, program guides, time referenced, station ID and conditional access information. PID 8187 is reserved for PSIP content.
- RTP: Real-Time Protocol
- The Real-Time transport protocol (RTP) is a Layer 4 protocol that provides end-to-end delivery services for data with real-time characteristics, such as interactive audio and video. Those services include payload type identification, sequence numbering, time stamping and delivery monitoring. Applications typically run RTP on top of UDP to make use of its multiplexing and checksum services; both protocols contribute parts of the transport protocol functionality.
- RTP-LDE: Loss Distance Errors
- (as per RFC3357) metric captures the spacing between the loss periods. LD is the difference in sequence numbers of two successively lost packets, which may or may not be separated by successfully received packets. LDE is the total number of LD errors.
- RTP-LPE: Loss Period Errors
- (as per RFC3357) metric captures the frequency and length of RTP packet loss once it starts. LPE is the total number of LP errors.
- RTP-SE: Sequence Errors
- (as per RFC3357) metric captures the total lost packets given difference in sequence numbers of two successive packets of a RTP stream.
- RVL: Remote Video Link
- A 10/100/1000 Ethernet port on select IneoQuest equipment that allows any video IP stream traffic entering the unit to be forwarded out this port for other uses. The RVL port can also modify the IP header of the selected IP stream, at line rate, not changing the IP stream behavior.
- Total CC Errors: Total Continuity Count Errors
- The Total Continuity Count Errors is the total number of errors in the MPEG transport stream for the given inspection period, based on the 4-bit continuity counter in the MPEG transport stream.
- Total PID/Mon/Err : Total number of Transport Stream PIDs/Monitored/Errored
- Total number of PIDs within the MPEG transport stream, as detected in the Program Table/ Total number of PIDs within the transport stream currently being monitored by system resources/ Total number of PIDs being monitored that are currently seeing errors.
- V-TSB: Video Transport Stream Bitrate
- The Video Transport Stream Bitrate is the measured bitrate of the encapsulated video transport stream within an IP stream. The arrival data rate of the IP packets is not considered. This measurement looks at the video transport stream payload bitrate by inspecting the PCRs within the transport stream being carried by the IP packets.
- ZAP: ZAP Time
- Time which it takes for a Multicast group stream to appear at a destination after an IGMP join is issued from the destination. For certain Video over IP applications, that use multicast groups to transport video, this can be referred to as channel change time.