DSCP Mapping
Overview
Differentiated Services Code Point (DSCP) Mapping profiles allow the mapping of DSCP to IEEE 802.1p pBit for untagged traffic entering the network from the subscriber side. If ingress traffic (traffic going from the subscriber port toward the network) does not have a VLAN tag, there is no 802.1p priority bit within the frame that determines how to handle the packet for Quality of Service (QoS) traffic management. This allows packets that were properly marked by the application at layer 3 to be marked at Layer 2 based on the incoming DSCP to the pBit mapping table.
To implement this feature, Panorama PON allows the configuration of DSCP to pBit values for mapping a profile for the connection. A new attribute is added to the connection profile, called the pBit mode.
How Does DSCP Work?
DSCP operates by assigning a specific code point value to each packet, effectively marking them for prioritization. Networking devices, such as routers and switches, use this DSCP value to determine the handling and queue placement of each packet.
Upon receiving a packet, the networking device scrutinizes the DSCP value. Packets with higher DSCP values are prioritized and placed in less congested queues, ensuring expedited delivery. This mechanism is particularly beneficial in a shared hosting environment where multiple websites are hosted on a single server. For instance, a packet carrying data for a high-traffic e-commerce site during a sale event would be given a higher DSCP value to ensure smooth and fast data delivery.
DSCP to P-bit Mapping table
The following shows the standard mapping used in many applications for the DSCP code points to pbit mapping table. The default profile in the EMS reflects this mapping.
| QUEUE | GRANNULAR SERVICE CLASS | PRIORITY/PRECEDENCE | DSCP | P-BIT | Per Hop Behavior (PHB) |
| 3 |
Network Signaling | Not Applicable | 48 | 7 | Expedited Forwarding |
| User Signaling | Not Applicable | 40 | |||
| Short Messages | Flash Override | 32 | 6 |
||
| Advanced Voice | Flash Override | 41 | |||
| Flash | 43 | ||||
| Immediate | 45 | ||||
| Priority | 47 | ||||
| Routine | 49 | ||||
| 2 |
Assured Multimedia Conferencing |
Flash Override | 33 | 6 | Assured Forwarding 41 |
| Flash | 35 | 5 |
|||
| Immediate | 37 | ||||
| Priority | 39 | ||||
| Routine | 51 | ||||
| 1 |
Broadcast Video | Not Applicable | 24 | 3 | Assured Forwarding 31 |
| Non-Assured Voice | Not Applicable | 46 | |||
| Multimedia Streaming (Video Streaming) |
Flash Override | 25 | |||
| Flash | 27 | ||||
| Immediate | 29 | 2 | |||
| Priority | 31 | 3 | |||
| Routine | 26 | 2 | |||
| Non-Assuring Multimedia Conferencing (Non-Assuring Video Conferencing) |
Flash Override | 28 | 3 | ||
| Flash | 30 | 3 | |||
| Immediate | 34 | 2 | |||
| Priority | 36 | 2 | |||
| Routine | 38 | 2 | |||
|
Low- Latency Data |
Flash Override | 17 | 3 | ||
| Flash | 19 | 3 | |||
| Immediate | 21 | 3 | |||
| Priority | 23 | 3 | |||
| Routine | 18 | 3 | |||
| Routine Reserved Nonconformance Marking |
20 | 2 | |||
| 22 | 2 | ||||
|
High Throughput Data (Real-Time Data Backup, Web hosting) |
Flash Override | 9 | 3 | Assured Forwarding 32 |
|
| Flash | 11 | 3 | |||
| Immediate | 13 | 3 | |||
| Priority | 15 | 2 | |||
| Routine | 10 | 3 | |||
| Routine Reserved Nonconformance Marking |
12 | 2 | |||
| 14 | 2 | ||||
| Operations, Administration and Maintenance | Not Applicable | 16 | 2 | ||
| 0 |
High Effort | Not Applicable | 0 | 0 | Default |
| Low Priority | Not Applicable | 8 | 1 |
DSCP Mapping Profile
The Profile /Template List of the DSCP Mapping profile contains a list of current DSCP Mapping profiles on the Panorama PON server that can be applied to any OLT managed by the server. A default profile is provided. This profile is assigned to connections when initially provisioned. The default profile can be edited, but it cannot be deleted.
The DSCP Mapping tab contains icons used to create, edit, provision, or delete profiles. Additional icons are provided to view the profile status when creating or editing a profile. These icons can be selected from the tool bar or by right clicking a listed profile and selecting the desired icon.
- To access DSCP Mapping right-click on the profiles (
) icon on the Main Window Toolbar.
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