Course Prospectus
ICA-XFG-201 is 2-unit advanced, instructor-led course module that offers detailed exploration of all aspects of packet header parsing and deparsing in P416/TNA. Course participants will learn how to define and parse complex packet headers in flexible, efficient, and robust manner that facilitates efficient processing in the match-action pipeline with proper handling and recovery from parser errors. The course introduces several important concepts and coding techniques related to packet parsing and covers TNA-specific externs, available in the parser and deparser. The course also covers the topic of parser efficiency and discusses typical problems that can be encountered when writing a complex parser.
This course is recommended to all data plane designers tasked with implementing non-trivial packet parsers.
ICA-XFG-201 is a part of Intel® Connectivity Academy XFG course series and can be taken either in-person or online.
Course Goals
Packet parsing is the first critical step in a P416 program, responsible for converting the external packet representation (byte stream) into the parsed representation (headers and metadata), suitable for processing in the match-action pipeline. Deparsing is the last step that reverses the process by converting P416 headers and metadata into the external representation. Due to the nature of packet processing in the high-speed systems, these steps critically influence the overall performance of the data plane algorithm. Tofino Native Architecture (TNA) as well as T2NA provide many advanced features that allow the skilled programmer to improve their code, make it more flexible and robust.
Upon the completion of the course, the students will:
- Learn how to design packet headers that facilitate the most efficient processing in the match-action pipeline.
- Learn how to parse complex headers with variable parts, including header stacks, variable length fields and user-defined fields with the emphasis on robustness and efficiency.
- Learn how to process and recover from various parser errors.
- Learn how to reuse complex packet parser code across ingress and egress processing.
- Learn how to add run-time parser flexibility by using the value_set objects.
- Learn how to perform incremental checksum updates using the Checksum() externs.
- Learn how to recover from packet mis-parsing using resubmit.
- Learn how to analyze parser efficiency using P4i tool and optimize it.
- Learn how to debug parser and deparser errors.
Detailed Schedule
Each unit consists of a 2-hour-long lecture (presentation) with one break and is followed by the hands-on labs.
In online format, each unit is conducted on a separate day – please consult the P4ica Calendar for details. Both morning and evening (Pacific Time) sessions might be offered to accommodate students from different time zones.
When conducted in-person, each 8-hour day constitutes 2 units.
UNIT 1
- Introduction
- Structuring and efficient parsing of L2 headers
- Strategies for parsing header stacks. Using value_set objects
- Using port_metadata extern
- Strategies for parsing IPv4 options and IPv6 extension headers
- Parsing User-Defined Fields (UDF)
UNIT 2
- Checksums: verification, computing the residual, (incremental) update
- Using resubmit to re-parse incorrectly parsed packets.
- Optimizing parser performance
- Understanding parser and deparser constraints and resolving typical compilation issues
Target Audience
This course is most suitable for data plane designers tasked with implementing P4 programs on Intel Tofino™ ASIC family devices.
Pre-requisites
- Successful completion of ICA-XFG-101
- Good understanding of standard network protocols, including Ethernet, IPv4, IPv6, TCP, UDP and MPLS
- Knowledge of Python language
- General understanding of Linux and ability to use it as a development system.
- When taken online, good and reliable Internet access for both online lectures and VM access is a must.
- When taken in-person, each participant is expected to have a laptop with a standard browser. No other software is required
How to Register
Class dates and times are announced on the P4ica Calendar Page ahead of time and you can register right on the site using the credit card or PayPal to pay for the tickets. The tickets can also be purchased through our partner, STORDIS, who provide additional services such as convenient invoicing or lodging booking for in-person courses. Please, contact your STORDIS sales representative for more details.
Please, note that most courses require all the participants to have a valid NDA and SLA (SLACA for academic and research organizations) in place. Their existence will be verified after the purchase, and you will be notified if additional steps are required, or the ticket will be refunded.
Logistics
ONLINE COURSES
To attend an online presentation, you will need to create a free Zoom account, associated with your work email address. Upon the registration, you will receive a link to the online event. You will also receive invitations to establish accounts on Slack and the P4ica Support Portal for lab support and materials access, also associated with your work email address.
A high-speed internet connection is required to attend the online presentation. Call-in numbers for higher voice quality might be provided, depending on the region. Please, connect to the online meeting 5-10 minutes before the start to work out all potential connection problems.
All necessary materials, including the presentation PDFs and lab exercises will be available through the P4ica Support Portal a day before the start of the class. We highly recommend that you print the presentation PDFs and use them to take notes. Alternatively, these presentations can be loaded on a tablet, where the notes can be taken with an electronic pen.
The information about the lab Virtual Machines will be provided at the end of the first lecture. VMs will be kept running throughout the duration of the course and shut down 48 hours after the end of the last class. Additional time can be purchased as a ticket add-on.
IN-PERSON COURSES
The location address and the arrival time can be found on the registration site and will be emailed to you as well. You are responsible for your own lodging and transportation; Academy stuff will be happy to provide some recommendations.
You will receive invitations to establish accounts on Slack and the Academy Support Portal for lab support and materials access, also associated with your work email address.
All necessary materials will be printed for you and are yours to take notes and take them back home. You will also get a lifetime access to the updated versions of these materials on the Academy Support Portal.
The information about the lab Virtual Machines will be provided at the end of the lecture. VMs will be kept running throughout the duration of the course and shut down 48 hours after the end of the last class. Additional time can be purchased as a ticket add-on.
Contact
For more information, please contact academy@p4ica.com.
Important Notes
P4ica, LTD is an independent training and consulting company. It delivers Intel Connectivity Academy classes under the special license from Intel, using approved materials and lab exercises. It also acts as a custodian for the Academy archives, thereby providing the alumni lifetime access to the class materials.
Intel® P4 Studio SDE is a software product, developed independently from the software, available via p4.org. Some components of the SDE were contributed by Intel to p4.org, others rely on the code from p4.org, but the goals of the projects, the tools, and the workflows are different. P4.org software is a community-supported project with many resources freely available. This class covers Intel® P4 Studio SDE and not p4.org software. Specifically, not covered are the Behavioral Model (BMv2), v1model and PSA P416 architectures and neither is P4Runtime protocol.
P416 compiler for Intel® Tofino™ and Intel® Switch Runtime Interface APIs are in active development as is the course module material. While Intel® Connectivity Academy team strives to introduce Intel customers to the leading-edge software, bugs, errors and omissions may occur. The later versions of these course modules might significantly differ from the earlier ones.
The course module material covers both Tofino and Tofino2 devices. Relevant enhancements and differences are emphasized and discussed whenever applicable.
The availability of each course is announced separately. Please, visit P4ica Calendar Page website for more information.
The online presentations may be recorded and may be published, in whole or in part, in various media, including print, audio and video formats without further notice. If you do not want to participate, you may choose to either keep your audio and video connections muted or turned off or leave the call. By choosing to remain, you are consenting to the recording of the session.