DPL Release Notes

Changes and New Features

This section describes the changes and added features in this software release:

Added support for large table sizes up to 32M
Added support for comparison operators in expressions
Added runtime debugger support for both Rx and Tx packets
Added extern to statefully track TCP sequence and acknowledgement numbers
Added idle timeout support for high update rate tables

Capabilities and Limitations

P4 Runtime

Table and Counter Object Size Constraints:
- The size of any P4 table or counter object must be a power of 2, and smaller than 2²³.
- A P4 table of size N allows for N-1 regular entries and 1 default entry.
P4 Controller Support:
- Only one P4 Controller can be connected to the DPL Runtime daemon at a time.

RPC Message Support:

Supported RPC Messages:

Write RPC:

Only CONTINUE_ON_ERROR atomicity is supported.
Batching is supported.
Supported entities:
- TableEntry
- CounterEntry
- DirectCounterEntry
- MeterEntry
- DirectMeterEntry
INSERT Operation:
- Supports regular entries only.
DELETE Operation:
- Supports regular entries only.

MODIFY Operation:

Supports default entry only.
Supports indirect and direct counter entries.
Supports indirect and direct meter entries.

Metering Limits:

Mode	Max CIR/PIR	Max CBurst/PBurst
Bytes	255,000,000,000	80,000,000
Packets	1,992,187,500	625,000

Mode

Max CIR/PIR

Max CBurst/PBurst

Bytes

255,000,000,000

80,000,000

Packets

1,992,187,500

625,000

We don't have a way to export this macro.

Read RPC:
- - Batching is supported.
  - Supported entities:
    - TableEntry
    - CounterEntry
    - DirectCounterEntry
    - MeterEntry
    - DirectMeterEntry
- SetForwardingPipelineConfig RPC
- GetForwardingPipelineConfig RPC
- StreamChannel RPC:
  - PacketIn
  - PacketOut
  - IdleTimeoutNotification
  - StreamError
Unsupported RPC Messages:
- Capabilities RPC
Unsupported Entities:
- ExternEntry
- ActionProfileMember
- ActionProfileGroup
- PacketReplicationEngineEntry
- ValueSetEntry
- RegisterEntry
- DigestEntry
Unsupported StreamChannel Request/Response Updates:
- MasterArbitrationUpdate
- DigestList / DigestListAck
- google.protobuf.Any

DPL Nspect

CSV output is no longer supported; the --csv argument has been removed.
JSON output is recommended for automated tools.
Limitation (P4DT-800): Programs using comparison operators are not supported and will result in an error.

DPL Debugger

Limitation (P4DT-800): Programs using comparison operators are not supported and will result in an error.

DPL Development Container

Running any of the scripts may result in the following error:

Error response from daemon: failed to create task for container: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: error during container init: exec: "/tmp/tmp.2STfXHaz03": is a directory: unknown: permission denied

As a workaround, do not use the community edition of docker installed from docker.ce, instead use the official release installed from docker.io.

Bug Fixes

Reference	Issue
4280302	Description: Concurrent counter reads from multiple threads by a P4Runtime client could theoretically lead to race conditions and incorrect results.
4280302	Discovered in version: 1.1.0
4467130	Description: API `dpl_rt_controller_table_entry_counter()` may hang forever if called right after adding a new entry using `dpl_rt_controller_table_entry_add()`.
4467130	Discovered in version: 1.1.0
4467855	Description: Direct counter data for some table entries may be missing from the output of the `./dpl_nspect.sh query` command.
4467855	Discovered in version: 1.1.0
4548630	Description: DPL RT Service erroneously allows inserting entries into keyless tables (tables defined without keys in the DPL program).
4548630	Discovered in version: 1.1.0
4552694	Description: DPL RT Service fails to correctly configure default actions for tables forwarding to High Update Rate tables, leading to packet drops when entries are missing.
4552694	Discovered in version: 1.1.0

Known Issues

The following are known limitations of the DPL Runtime daemon service.

Reference	Issue
4400696	Description: Counter resource is limited to 16M hardware counters, but a portion is reserved by the Kernel driver, reducing the available count for user applications. Exceeding this limit may cause counter allocation failures.
	Workaround: N/A
	Reported in version: 1.2.0
4417192	Description: Modify Header actions are limited to 16M hardware counters, but actual usable counters are fewer since some are reserved by the Kernel driver. Exceeding this limit may result in insertion failures.
	Workaround: N/A
	Reported in version: 1.2.0
4259599	Description: Packets with double VLAN tags (Dot1AD followed by Dot1Q) are received with reversed tag order.
	Workaround: Disable RX VLAN offload on the VF using: `ethtool -K <vf_netdev> rxvlan off`
	Reported in version: 1.2.0
4437411	Description: Packets with broadcast MAC ff:ff:ff:ff:ff:ff transmitted from VFs are not supported by DPL actions `nv_add_entry` and `nv_send_to_controller`.
	Workaround: N/A
	Reported in version: 1.2.0
4439323	Description: Modifying eSwitch multiport mode (enable/disable) while DPL RT Service is active causes system hang.
	Workaround: Stop the DPL RT Service before changing `esw_multiport` settings.
	Reported in version: 1.2.0
4540834	Description: Entries insertion/deletion rate may degrade when using tables with idle timeout or delayed counters.
	Workaround: Adjust the polling interval to balance accuracy and performance on the DPL admin tool using: `dpl_admin set-idle-timeout-polling-interval -d <device_id> -i <interval_in_sec>`
	Reported in version: 1.2.0
4548632	Description: 32M sized table is not supported.
	Workaround: Use 2 16M tables.
	Reported in version: 1.2.0
1141	Description: Debugging packets from the second wire port P1 is not supported.
	Workaround: Use wire port P0 for debugging packets.
	Reported in version: N/A

Last updated: August 27, 2025