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STTP (IEEE 2664)JEFF PARKER, P.E.

8/5/2020

2

STTP (IEEE 2664)PROTOCOL OVERVIEW

STTP Overview

• Streaming Telemetry Transport Protocol

• Encrypted (TLS)

• Lossless Compression

• Publish/Subscribe Security

• Real Time and Historical Channels

• Includes Metadata

4

STTP (IEEE 2664)PROTOCOL DETAILS

End to end

encryption, full

control of access per

data point and client.

TCP utilized web

standard TLS

encryption layer.

Security

• TLS is fully supported over TCP

• UDP can be encrypted with

AES keys

• X.509 Certificates

• Access control list (ACL) always

on

Bandwidth savings

over other protocols.

Significant bandwidth

savings can be

achieved with TCP

utilizing TSSC.

Lossless Compression Options

• Time-series Special

Compression (TSSC) TCP-only

• Deflate Algorithm (TCP/UDP)

• No Compression (TCP/UDP)

Publisher can set

access limits on data.

Subscriber saves

bandwidth by

choosing only

needed data.

Publish/Subscribe

• Secured with ACL

• Publisher sets Allow/Deny Lists

for Points and Groups (Users)

• Subscriber chooses from

available points

Data restoration after

connection

interruption.

Application data

lookup for events.

Data Recovery & History

• Secured with ACL

• Secondary channels for

Historical Time Series Request

Exchange common

data such as GPS

coordinates, naming

conventions.

Send custom data

such as notes and

reference data.

Metadata

• Secured with ACL

• Tabular Metadata

• Custom Metadata

TCP allows for the full

feature set of STTP,

including web

standard TLS.

UDP only

transmission limits

protocol features and

data format

negotiation.

TCP/UDP

TCP UDP

Compression TSSC, Deflate Deflate

Encryption Full TLS AES cert only

Packet

Transmission

Lossless Lossy

STTP Feature Set Full – Command,

Pub/Sub, History,

Metadata

Limited

Notes Separate TCP

channel needed

to establish

connection.

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STTP & C37.118PERFORMANCE COMPARISON

12

-

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

0 1000 2000 3000 4000 5000 6000 7000 8000 9000

IEEE 2664

IEEE C37.118

Po

ints

Per

Mb

ps

of

Ban

dw

idth

Number of Measurements at 30 points/sec

1,200

1,700

STTP vs. C37.118 Bandwidth

Lossless

compression

enables

greater STTP

throughput.

Lowers latency on

high quality streams.

Allows for dropping

of single bad data

point instead of entire

frames.

Latency

• Latency consistent even with

high point count

• Streams per point, instead of

per time frame

15

IEEE C37.118 Latency

IEEE C37.118 Latency increases significantly with high point count.

16

STTP Latency

STTP Latency

consistent even

with high point

counts.

Testing Raw Data

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STTP Rollout

Allows control centers

to establish an

encrypted and access

controlled

information exchange

of PMU stream data

and metadata.

Requirements

• Information Gateway (SIEGate)

• Exchanging of TLS certificates

• Firewall/Routing

• Sufficient bandwidth (Similar to

C37.118)

• Vendor Support (GPA, EPG, etc)

References

• STTP Specification

https://github.com/sttp/Specification

• A COMPARISON OF PHASOR COMMUNICATIONS PROTOCOLS

https://www.osti.gov/biblio/1504742

• GPA STTP Peer Review

https://www.gridprotectionalliance.org/pdf/ASPPeerReviewJune2019.pdf

• GPA STTP

https://www.gridprotectionalliance.org/technology.asp#STTP