Download DQSA

The Ideal Network
DQSA
(Distributed Queue Switch Architecture)
Or
Routerless Routing and Switchless Switching
Presented to Project Rescue Group
UCI
By
Graham Campbell
Chief Science Officer
Ether2 Corp
May 25, 2017
Ether2 Corporation
1
Introduction
• DQSA (Distributed Queue Switch Architecture) is a
family of protocols developed at The Illinois
Institute of Technology.
• Basis of DQSA is almost ideal MAC (medium
access control) that is effective regardless of
speed, distance, or medium.
• Ether2 Corp. has acquired the exclusive rights to
this patented technology.
May 25, 2017
Ether2 Corporation
2
Background of MACs
• The telephone party line utilized one of the earlier MACs
•
•
•
•
which was either good manners or hollering louder.
Communications between computers is subject to same
economics:
– Direct connections often underutilized
– A plus - machines, unlike humans, can increase
transmission rate.
Hollering was no longer a solution.
How did computer communications develop?
Introduction of Aloha at U of Hawaii in the late 60s started
search for ideal MAC.
May 25, 2017
Ether2 Corporation
3
Characteristics of the Ideal MAC
1. Immediate Access.*
Shared Bus
2. Bus Fully Utilized.
3. Average Delay that of M/D/1 Queue.
4. Delay is Predictable.
5. FIFO with Optional Priorities.
6: Distributed Control - No Master Station.*
7. QoS - Provide Guaranteed Bandwidth.
8. Topology Independent.*
9. Idle Nodes do not use Resources*.
10. Serves geographic area of any size.
* Only 1, 6, 8 and 9 supported by Ethernet.
May 25, 2017
Ether2 Corporation
4
A Router Has Five Characteristics
Output Ports
(2) If Traffic
Present, Line is
Fully Utilized
(1) If Line is Empty,
Transmit
Immediately
(5) FIFO Operation
with Optional
Priorities
(4) Delay for Specific
Packet is
Predictable
(3) Average Delay is
that of M/D/1 Queue
May 25, 2017
Output Buffers
Input Buffer
Input Ports
Ether2 Corporation
Arriving Traffic has
Poisson Distribution
5
DQSA Has Everything -- How?
• DQSA utilizes, in addition to a data slot, three control
minislots (CMS) that are used to (1) reserve data slot(s),
and (2) resolve contention.
DATA SLOT
• DQSA utilizes features of existing protocols:
–
–
–
–
Aloha/CSMA
Control Minislots
DQDB
Stack Protocols:
• Next slide compares DQSA with the ideal, note the reasonable
delay at 0.95 traffic.
May 25, 2017
Ether2 Corporation
6
DQSA Delay
M/D/1 - Ideal
DQSA
15
12
9
Delay in
Slots 6
3
1
0.9
0.7
0.5
0.3
0.1
0
Offered Traffic Load
May 25, 2017
Ether2 Corporation
7
COMPARISON OF THROUGHPUT
S ( Throughput )
1
DQSA
M/D/1
(Perfect)
Non-persistent
Slotted CSMA
0.8
Non-persistent
CSMA
0.6
0.1 persistent
0.4
1-persistent
CSMA
CSMA
Slotted
ALOHA
0.03 persistent
CSMA
Pure ALOHA
0.2
0.01
May 25, 2017
0.1
1.0
G ( Offered Load )
Ether2 Corporation
10
100
8
PDQSA (Priority DQSA)
(Mixture of High and Normal Priority Traffic)
Total Load 90%
High Normal
0.10
0.80
0.20
0.70
0.30
0.60
0.40
0.50
0.50
0.40
0.60
0.30
0.70
0.20
0.80
0.10
May 25, 2017
Delay in Slots Average
High Normal Delay
4.29
9.19
8.64
4.36
9.74
8.54
4.4
10.59
8.53
4.52
11.77
8.55
4.66
13.28
8.49
4.78
15.58
8.38
5.19
19.4
8.35
5.81
28.37
8.41
Ether2 Corporation
9
XDQSA(Extended DQSA)
• In the seminal DQSA protocol (DQRAP), each
transmission into a CMS is a request to reserve a single
dataslot.
• In XDQSA each transmission in a CMS is a request to
reserve a multiple number of dataslots.
• Variable length packets are segmented and the
segments (cells) transmitted with no further
encapsulation.
• Big Plus! XDQRAP requires but two minislots to achieve
100% utilization of dataslots.
May 25, 2017
Ether2 Corporation
10
DQSA Segmentation and
Transmission
IP Datagram – 500 bytes
Ethernet Hdr
(16 bytes)
IP Datagram Encapsulated in Ethernet Frame
Ethernet Trlr
(4 bytes)
IP Datagram
Ethernet Frame will be segmented into 520/64 =
nine 64-byte chunks. Station transmits request in
minislot for nine slots. When request is
successful, station joins queue and transmits the
nine segments.
64-byte chunk
Minislot request
from another
station
May 25, 2017
Ether2 Corporation
11
How Robust is DQSA?
• Arrival of multiplicity N is resolved in less than N
dataslots ensuring 100% throughput.
• Errors in reading CMS and retransmission in CMS do
not affect data transmission unless arrival of multiplicity
N not resolved in N dataslots.
• DQSA can sustain up to 10% error rate in cms
before data throughput drops below 1.
May 25, 2017
Ether2 Corporation
12
How About QoS?
• DQSA provides three general levels of service:
1 Best Effort: Equivalent to conventional transmissions under
DQSA where average delay is 8.25 slots at offered traffic of
90%.
2 Priority using PDQ: Delay equivalent to lightly loaded
network. PDQ provides ~4 slot delay for 20% high priority in
90% total traffic.
3 Guaranteed Service: DQSA provides equivalent of TDM-like
channels intermixed with random access.
• DQSA supports intermixed synchronous and
asynchronous traffic.
May 25, 2017
Ether2 Corporation
13
Why DQSA Works
• In networks traffic tends to converge before diverging. Often
expensive switches are functioning as congestion prone hubs.
• Networks since the time of Bell have been designed to support
actual traffic rather than potential traffic. Telcos make best return
on investment by selling capacity that is not used, e.g., oversubscribing.
• DQSA is the ideal architecture for both of the above – perfect
queuing makes for both optimal convergence and for supporting
over-subscription.
• Let us look at examples.
May 25, 2017
Ether2 Corporation
14
A DQSA G.shdsl System
DQSA Enhanced
G.shdsl Chipset
Ether2 Qmux
T1 - OC3
Up to 32 ports. Multiple 32-port units can be ganged
to a single output port.
May 25, 2017
Ether2 QMux -- a DSLAM Replacement at much less
cost. Supports QoS. Output speed flexible from T1
to OC3. ATM or IP.
Ether2 Corporation
15
Support Voice, Video and Data in Combat
UAV can dynamically
acquire sync channel
Radio tower
DQSA achieves 100% utilization
of data slots with
short transmissions.
May 25, 2017
Support of virtually unlimited number
of contending users ensures easy tracking of
tens of thousands of troops and
vehicles.
Ether2 Corporation
16
A DQSA SAN
Terabyte+ Storage Units
1 Gbps DQSA
May 25, 2017
Ether2 Corporation
10 Gigabit/s Backbone
DQSA Control
17
DQSA and Cell Systems
• Supports up to three times
number of calls.
• Carrier signaling and spread
spectrum.
• Dynamically allocated fixedbandwidth channels intermixed
with voice packets.
• Overloading accommodated .
May 25, 2017
Ether2 Corporation
Radio tower
18
DQSA Eliminates the Routers
San Francisco
Denver
St. Louis
Philadelphia
New York
Legend
HQ DataBase
Branch Office
Customer Premises
Ether2 IAD/NIC
Carriers utilize their basic SDH synchronous plant, e.g., T1, DS3, OCx.
Customer offices are connected to their respective virtual or physical
private networks via Ether2 IADs/NICs. The latter connect directly into
the SDH infrastructure.
SONET Ring,
Central Office
May 25, 2017
Ether2 Corporation
19
Ether2 Ethernet-Compatible Cluster
DQSA Beacon
Generator
Passive
Fiber Hubs
(32 taps)
Processor(s)
Repeater for
Power Budget
1- 10 Gbps
Fiber
May 25, 2017
Ether2 Corporation
20
Features of DQSA in Clusters
•
•
•
•
•
•
Fairness
Global Operations
Multicast/Broadcast
Channels
Full utilization with short messages
Low Latency
Latency (μsecs)
1 Gbps
2 Gbps
5 Gbps
10 Gbps
40 Gbps
4.0
1.6
0.8
0.4
~4 x Prop
Delay
(4.5 slots)
May 25, 2017
Ether2 Corporation
21
Ease of Implementation
• The basic DQSA network consists of a fourstate logic machine at each node.
• Sits above the physical layer – any medium,
and below the network layer – DQSA just
slides in.
• A DQSA switch can look like an Ethernet
switch, an ATM switch, an IP switch, or any
other type of switch.
• Potential applications – virtually unlimited.
May 25, 2017
Ether2 Corporation
Application
Transport
e.g. TCP
TCP
Network e.g. IP
DQSA
Physical
22
CDQ (Cascaded Distributed Queue)
Qnodes
Fiber Optics
Passive Tap
Metropolitan/Regional
DQSA Networks
CDQ utilizes the Qnode. The Qnode provides the equivalent of a routing function by
reducing the routing decision to a “yes or no” thus eliminating congestion. Local
DQSA networks are “attached” between the Qnodes.
May 25, 2017
Ether2 Corporation
23
Conclusion
• DQSA represents a paradigm shift in switching.
• DQSA will enable final convergence of voice,
video and data.
• Ether2 has built 12 NICs and two hubs and will
be developing software on a prototype 100 Mbps
cluster in the next 3 months.
• Ether2 is interested in partnering.
• Graham Campbell 310.913.4383
[email protected]
May 25, 2017
Ether2 Corporation
24