Designing SMPTE 2059-2 PTP Networks

Presenters : Thomas Kernen - Mellanox

Year : 2019

dlp_document_download : AIMS IP Showcase IBC 2019 September 2019 Curated by Video Services Forum vsf.tv 1 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 C U R A T E D B Y Avoiding Traps and Pitfalls When Designing SMPTE 2059 -2 Networks Thomas Kernen – Staff Architect Mellanox Technologies I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 2 AIMS IP Showcase IBC 2019 September 2019 Curated by Video Services Forum vsf.tv 2 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 3 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 AIMS IP Showcase IBC 2019 September 2019 Curated by Video Services Forum vsf.tv 3 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Timing accuracy for ST 2110 networks • IEEE 1588 Precision Time Protocol • SMPTE 2059 -2 PTP Profile • Slave to GrandMaster offset • Max +/ -500ns • Well disciplined Endpoints • PTP stack stability • Filters, control loops • Well designed networks • PTP aware devices • Boundary, Transparent Clocks 6 AIMS IP Showcase IBC 2019 September 2019 Curated by Video Services Forum vsf.tv 4 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 What could possibly go wrong? •Deadlines •Planning, lack of PTP experience •Lack of in -depth testing •Quality of project gate reviews •Hardware/software limitations •Efficiency of fixes/workarounds •Unscheduled personnel events (reality check) •"Other urgent project" that needs taken care of I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 The clock is ticking AIMS IP Showcase IBC 2019 September 2019 Curated by Video Services Forum vsf.tv 5 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Timing strategy •PTP message rates ‒Don’t underestimate the impact of changing these rates ‒Must be consistent across the whole PTP domain ‒If changing defaults, test and validate corner cases, and test again! •Managing the GM hierarchy (BMCA dataset) ‒Priority1, Clock Class, Clock Accuracy, Clock Variance, Priority2, Port ID ‒Setting P1 is like using a sledgehammer, P2 is generally more appropriate •Where to connect the GMs? (Spine or leaf) ‒It depends, but really it shouldn’t make a difference (port cost/availability) 9 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Network design •PTP aware vs. non aware •Transparent Clock, Boundary Clock? •IPv4, IPv6 transport (Link Local Addresses) •Multicast, Mixed Mode, Unicast messaging? •PTP message path selection (in -band, mgmt ) •PTP traffic isolation using VRF/LAG/VLAN •Management TLV messages ( behaviour ) AIMS IP Showcase IBC 2019 September 2019 Curated by Video Services Forum vsf.tv 6 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Basics: Securing all hosts •Authentication, Authorization and Accounting (AAA) ‒Connection attempts, timestamp, username, IP address, commands useT •Access Lists (ACLs) to limit who can reach the device, on all interfaces •Only use TLS encrypted transports (SSH, HTTPS, …) for all sessions •No unprotected interfaces! Unauthenticated GM web interface •Don’t forget the physical ports too! Console, serial, auxiliary •Disable unused services, interfaces, protocols •Threat modeling 11 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Securing the PTP network •Traceable time sources ‒Source diversity, frequency & time traceable •Acceptable Master Table (AMT) ‒Prevent remotely connected device from attempting GM role takeover •"Forced master" ‒Prevent locally connected device from attempting GM role takeover •Threat modeling (again) 12 AIMS IP Showcase IBC 2019 September 2019 Curated by Video Services Forum vsf.tv 7 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Monitoring •Broadcast/Network Controller PTP dashboard ‒Realtime visibility and overview of PTP health •1pps signal comparison between GM & SLAVE ‒Out of band signal validation at specific points •Packet analysis of PTP messages (online/offline) •PTP message counters for all nodes (trigger alarms) •Slave port monitoring ‒Transfer slave information to monitoring node ‒Standardized in upcoming IEEE 1588 v2.1 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Diversity & Failure testing •Design for diversity ‒ST 2110 with ST 2022 -7 for media ‒PTP redundancy != standard feature ‒Stack specific implementations ‒Different designs = different results •Test for partial and total failure ‒Define key metrics ‒Recovery time (media and PTP) ‒What is gating this? ‒Is it important to reduce? AIMS IP Showcase IBC 2019 September 2019 Curated by Video Services Forum vsf.tv 8 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Vision vs. reality = Compromise •Do your research ‒Vendor inputs, not just the datasheet ‒Presentations of existing projects ‒Industry publications, reference designs •Cross check information ‒Early days, limited experience, inaccuracies •You will need to compromise ‒Common feature baseline & operating model I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Decision tree = Methodology •Make a plan and stick to it! ‒Uncertainty will just make things worse •Test & validate: ‒your design methodology ‒your vendors announced capabilities ‒end to end with all vendor equipment interconnected, including failure scenario •Work with your vendors around their limitations, constructive process •Schedule the fixes, enhancements, feature requests and deal breaker deadlines •Finally, mitigate implementation limitations once everything else has been done AIMS IP Showcase IBC 2019 September 2019 Curated by Video Services Forum vsf.tv 9 I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Plan, test, rinse, repeat •All PTP networks are equal ‒Some more than others •Your network will always be unique ‒Slight differences = big impact •Plan ahead, mitigate limitations, think again •Test again, again, and again, and some more I P S H O W C A S E T H E AT R E AT I B C 2 0 1 9 : 1 3 –1 7 S E P T 2 0 1 9 Thank you Thank you to our Media Partners Thomas Kernen, Mellanox Technologies tkernen@mellanox.com 18