Network Technologies DVB-ASI to IP Appendix F Quality of service Setting Packet priority, Mpls

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ASI-IP-GTW User's Manual

12 Appendix F: Quality of service – Setting Packet priority

Normal IP routing is by best effort. This does not work well for broadcast television as the video and audio components needs to be transport as a continuous flow of packets without inference caused by other traffic over the internet. There are different techniques to secure a high quality of service. The main ones are:

oMPLS (Multi Protocol Label Switching) o Layer 3 routing priority

o Layer 2 routing priority

12.1 MPLS

In networks running MPLS, the packets are forwarded along a predefined path from an ingress router to an egress router. Packet switching is then done according to the label and packets will be switched expediently. The MPLS label is added to the IP packet by the ingress router and removed on the egress router. The labelling is done on the basis of packet classification.

12.2 Layer 3 Routing

An alternative technique to get QoS is to use layer 3 routing and give video content packets higher priority than other data. IP packets are put into queues according to their priority. Packets with high priority are forwarded expediently and have a lower probability to being discarded due to buffer overflow.

There are two ways prioritize IP packets called Differentiated services (Diff-serve)or by the precedence bits (TOS). Both these method use the same bits in the IP header and both of them are in common use.

IP precedence values range from 0 to 7.

DSCP values range from 0 to 63.

Figure 43 Differentiated services (Diff-serve) or by the precedence bits (TOS )

Layer 3 prioritisation may also be combined with MPLS where layer 3 routing is used in the aggregation network and MPLS in the core network. The DSCP priority setting may be used for MPLS tagging.

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Contents DVB-ASI to IP Gateway This page is intentionally left blank Important notice Rev Date SW ver CommentPage Table of Contents Options 12.1 Who Should Use this Manual IntroductionPurpose of this Manual Contact Information What Equipment is Covered by this ManualSoftware versions Summary of FeaturesRole of the ASI-IP-GTW in a Typical System Page Indicator Colour Description Guided TourUser Interface Front Panel DescriptionConstruction Hardware OptionsSoftware Options Functionality Max value DescriptionIntroduction Installing the EquipmentInstalling the Equipment Equipment access To fix the equipmentTo cable the equipment VentilationTo connect the equipment ASI portPower Cable and Protective Earth PowerAC Power Supply USA Nema 5-15P Protective Earth /Technical EarthUK BS Pin placement Specification Optional DC Power SupplyConnecting the Video Gateway to the AC Power Supply ASI ports Signal ConnectionsIntroduction DVB ASI output Ethernet data portDVB ASI input LEDs Ethernet management portPowering Up/Down Before Powering upPowering Up Powering DownOperating the Equipment Changing the IP address of the unitLooking at the WEB interface Overall statusMain tab Sub-tab Description SnmpStatus Device Info Product type ASI-IP-GTWNetwork MainAdvanced 1.22 SFPDevice info page, Network and SFP sub-page Time settings Shows the sub-page for time setting used for alarm reportsAlarms SnmpSnmp tab Ping Ping tabPage Shows the sub-page for user security password protection SecurityMain Input ConfigurationIP TX Input Status IP TX ParametersIP TX Status FEC Settings IP TX FECPage Static MAC setting Ethernet SettingsVlan settings Ping Settings Ping page of an IP transmitterOutput Configuration IP RXIP RX Status Output StatusIP RX Parameters FEC sub-page of an IP receiver Page Ethernet sub-page of an IP receiver Ping page of an IP receiver Advanced Tab Advanced TabPage Transmitted Network streams NetworkData Network Interface Status Shows the Network page for a unit configured to IP-RX mode Received Network streamsSaving a Configuration Save/LoadLoading a Configuration Save/Load page when saving configurationOptions 1PPS/10MHz interface modulesSeparate 10MHz/1PPS module 2 1PPS interfaceOperating the 1PPS/10MHz interface module Shows the layoutLED descriptions LED description for separate 1PPS/10MHz interface moduleRIPv2 functionality Shows the layout of the RIP-2 screenPage Functional Description IP Transmit ModeEquipment Description Management IP Receive ModeIP Bi-directional Mode Page Alarm Severity level Description Overview of Video over IP Protocol mappingUDP Mode Data Flow Block DiagramsForward Error Correction FEC Page Maintenance Preventive Maintenance and Fault-findingPreventive Maintenance Preliminary Checks Fault-findingFault finding Philosophy PSU LED Unlit / Power Supply Problem Alarm LED lit / Alarm condition Fans Not Working / OverheatingStep Action If the result of action is Yes Check Fan RotationAlarm Description Error source Progress Bitrate estimationGeneral Disposing of this EquipmentTo return the unit Appendix a Glossary Page Page Page Appendix B Technical Specification DVB ASI portAlarm relay and maintenance port specification Ethernet data portEthernet management port ProtocolsAC Mains Input DC Mains inputPhysical Details Safety Environmental ConditionsCompliance1 Electromagnetic Compatibility EMCCE Marking Interface to public telecommunication systemAppendix C References Appendix D Upgrade of Features Ex. http//192.168.0.100/upgradeFeature upgrade Feature upgrade dialogue Upgrade SW Appendix E Upgrading SoftwareSW load progress Layer 3 Routing Appendix F Quality of service Setting Packet priorityMpls ASI-IP-GTW Configuration Layer 2 priority