Joint IEEE-SA and ITU Workshop on Ethernet
Stream Reservation Protocol
(SRP)
Craig Gunther
Senior Principal Engineer
Harman International
Geneva, Switzerland, 13 July 2013
What is SRP?
The dynamic control protocol used to
create a path through a network for
rank-based, latency guaranteed
bandwidth reservations within a
heterogeneous AVB Cloud
IEEE 802.3 “wired” Ethernet
IEEE 802.11 Wi-Fi
MoCA (Multimedia over Coax Alliance)
Geneva, Switzerland, 13 July 2013
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What is SRP (continued)?
Bridges do not allow a reservation
unless they can provide the
requested QoS
Part of the “2011 AVB Protocol Suite”
802.1AS: GENERALIZED PRECISION TIME PROTOCOL
802.1Qav: CREDIT BASED SHAPER (Q:34)
802.1Qat: STREAM RESERVATION PROTOCOL (Q:35,C)
802.1BA: AUDIO VIDEO BRIDGING (AVB) SYSTEMS
Geneva, Switzerland, 13 July 2013
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SRP terminology
TALKER: Source of a stream
LISTENER: Destination for a stream
DOMAIN: A connected set of Talkers,
Listeners, and Bridges that support
the same priority for an SR class
RESERVATION: A network path
between a Talker and its Listener(s)
that supports the requested QoS
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Reservation Process
A simple three step process:
1.
2.
3.
Establish a Domain
Talker Advertises a stream
Listener(s) Attach to the stream
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How do SRP Domains work?
Establish the Domain Boundary
(Q:34.2*)
Must have same priority value for SR
class, otherwise it’s a boundary, and:
Conflicting ingress priority is regenerated to
protect SR class priorities and queues (Q:6.9.4)
Talker Advertise -> Talker Failed (Q:35.2.3.1)
Note: The AVB Cloud is an intersection of an
SRP Domain and a gPTP (802.1AS) Domain.
* Q:34.2 is a reference to 802.1Q-2011 Clause 34.2
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Four Domain example
AVB domain 1
AVB
end
station 8
AV
Bridge 1
AVB
end
station 7
AVB domain 2
AVB
end
station 3
AV
Bridge 2
AVB
end
station 5
AV
Bridge 3
AVB
end
station 4
SR class A
uses priority 5
SR class A
uses priority 3
AV
Bridge 4
AVB
end
station 9
Non-AVB
end
station 11
SR class A
uses priority 3
AV
Bridge 5
AVB
end
station 1
AVB
end
station 2
AVB domain 3
SR class A
uses priority 4
AV
Bridge 6
AVB
end
station 6
AVB domain
AVB domain boundary port
LAN carrying non-AVB traffic
AVB
end
station 10
Geneva, Switzerland, 13 July 2013
LAN carrying AVB traffic
AVB domain 4
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How do SRP Reservations work?
TALKER and BRIDGE(S)
Stream Registration
Talkers advertise one or more streams
and specify the QoS requirements
Bridges propagate those advertisements
throughout the network
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How do SRP Reservations work?
LISTENER and BRIDGE(S)
Stream Attach
Listener(s) request the stream
Bridges
Add associated ports to VLAN Membership
“Nail-up” the path and configure the stream
shaper and traffic forwarding
Update streamAge
Forward Listener Ready toward Talker
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Reservation process
Talker Advertise propagates everywhere
Listener Ready propagates towards Talker
Talker
#1
Adv
erti
Rea ses1
dy
S1
ises1
Advert
StreamS1
AVB Cloud
s1
tise
r
e
Adv dy S1
Rea
Ad
ve
s1
rti
se
se
rti
s1
ve
Ad
Listener
#n
Listener
#1
Talker +
Listener
Geneva, Switzerland, 13 July 2013
Talker
#n
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Who uses SRP today?
Professional Audio products
Installed Sound
(airports, churches, theaters,
amusement parks, sports venues)
Portable PA
Tour Sound
(club bands)
(outdoor concerts, touring bands)
Automotive
Infotainment
Control and Command - eventually
Industrial Control
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What’s next for SRP?
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Requests from current SRP users
Automotive
Statically define reservations
Faster startup times
10x to 100x reduced packet rates
Traffic shaper selection (A/V vs control)
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More Requests
Professional, Industrial and Consumer
Configurable SR classes, priorities and
default VLAN-IDs
Support link aggregation
Explicit path selection
Latency and Energy Efficient Ethernet
Support for Layer 3
Two-way reservations
Multiple Talkers per stream
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IEEE 802.1Qcc
Requesting authorization for new
work
PAR:
http://www.ieee802.org/1/files/public/docs2013/newp802-1qcc-draft-par-0513-v1.pdf
5C:
http://www.ieee802.org/1/files/public/docs2013/newp802-1qcc-draft-5c-0513-v1.pdf
Targeted for 2017 completion
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THANK YOU
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