This document discusses the synergy between circuit switching and packet switching technologies in telecommunications networks. It covers: 1) The shift in the telecom market to more packet switching; 2) Trends in switching technologies showing increasing speeds; 3) Advantages of circuit switching for network-on-chip applications; 4) The US Department of Defense transitioning some networks to packet switching while maintaining circuit switching for classified networks; and 5) Lessons for the Russian telecom company Rostelecom regarding their network architecture choices. The conclusion is that circuit switching and packet switching will likely coexist for the foreseeable future, with each having advantages depending on the specific network application and requirements.

1. ON THE SYNERGY OF CIRCUITS AND
PACKETS
M. A. SNEPS-SNEPPE
Ventspils University College, Latvia
Central R&D Telecom Institute (ZNIIS), Moscow
sneps@mail.ru
DISTRIBUTED COMPUTER AND COMMUNICATION NETWORKS
(DCCN-2015)
October 20, 2015, Moscow
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2. Contents
1. World telecom market: a slow shift to PS
2. Switching Technology trends in telecom networks
3. Network-on-chip revolution: CS vs. PS
4. U.S. DoD dilemma: CS vs. PS
5. Lessons for Rostelecom
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3. 1. World telecom market: a slow shift to PS
Worldwide Distribution of Telecom Service Revenue in 2015 [Gartner survey].
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4. Strategic Market Opportunities 2015, Worldwide (Billions of Dollars)
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5. 2. Switching Technology trends
According to Moor’s law , the computer productivity was increased twice and
the price decreased twice every 18 months.
The optical fiber speed on each used wavelength was doubled every 12 months.
With the speed 80 Gbit/sec on channel, 160 channels can transfer 12.8 Tbit /s.
That exceeds the bandpass of all telephone networks existing in the world.
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6. Functional blocks of a packet switch (router)
•The framing module extracts the incoming packet from the link-level frame.
•A route lookup determines its next hop, and the egress port.
•Right after the lookup, several operations are performed; decrementing the
Time-To-Live field, updating the packet checksum, etc.
•Then the packet is sent to the egress port using the router's interconnect
•Conflicting packets have to be queued in the ingress port, the output port, or both.
•In the output linecard, router performs scheduling for QoS guarantees.
•Finally, the packet is placed in a link frame and sent to the next hop.
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7. Functional blocks of a channel switch
Comparison of power consumption and price, 2012
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8. SDN based Transition from packet switch to
MPLS-OTN (Optical Transport Network)
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S Das, G Parulkar, and N McKeown „Rethinking IP Core Networks”
VOL. 5, NO. 12/DEC 2013/J. OPT. COMMUN. NETW

9. AT&T’s US IP core network
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10. Overall Capex is reduced by 60% - from “IP over WDM” to
“IP and Dynamic Circuit Switching”
S Das, G Parulkar, and N McKeown „Rethinking IP Core Networks”
VOL. 5, NO. 12/DEC 2013/J. OPT. COMMUN. NETW 10

11. Switching Technology forecast
Packet switching will continue to exist at the edge of the
network. The packet-switched network should ideally
gather traffic from disparate sources, and multiplex it
together.
At the core of the network, we expect the circuit switched
transport network to remain as a means to interconnect
the packet switched routers, and as a means to provide
high reliability, and performance guarantees.
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12. 4. Network-on-chip (NoC) revolution
Intel Datacenter-on-Chip Transformation: tera-scale chip multiprocessor
(CMP) can replace the whole data center with 63 systems and 130
processors.
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13. Single-crystal microchip (NoC)
A single crystal houses a lot of elements: the central processing unit (CPU);
the memory (MEM); the input/output (I/O); and the USB interface, Ethernet, etc.
They mainly communicate using buses (bus), but …how to build the central part —
the switching network between the buses.
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14. Traditional Packet switching NoC
Network on a chip with 9 nodes (left); each node S represents a router
with 4 inputs and outputs (right).
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15. The mechanism for transmitting message received
by the chip input
Dividing messages into shorter pieces while the message is transmitted by the chip.
Phit is a unit of data that is transferred between nodes in a single cycle of the chip.
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16. CS NOC: MPEG-4 decoder (Taiwan): 2006
Experimental results for two different MPEG-4 decoder architectures
In 2006, the engineers of a Taiwan university presented MPEG-4 decoder prototypes
in two implementations: СS NоC and РS NоC based on 0.18 µm technology.
The test results clearly show the advantage of circuit switching for NoC.
The most notable is the difference in power consumption — by 45 times.
The MPEG-4 standard is mainly used for broadcasting (video streaming),
recording movies onto a CD, for video telephony (videophones), etc.
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17. On CS NOC advantages (Stockholm): 2013
In 2013, Swedish engineers (the Royal Inst Tech, Sweden) compared:
(1) СS NоC with a 4 х 4 switching field;
(2) PS NоC with the same field: 4 virtual channels and 4 buffers
(3) PS NоC: 16 virtual channels and 16 buffers
In a vast range of loads, circuit-switched CS NoC is more effective.
If the packets are longer than 500–800 bytes, then CS NoC is more effective.17

18. 2014: Intel Labs demos crazy-efficient NoC
In February 2014, Intel announced the development of a phenomenal chip
that contains a network consisting of a matrix of 256 nodes (16 x 16).
This network is a switch board with 20.2 terabit/s bandwidth.
This chip is based on 22-nm trigate CMOS technology.
The CS mode has the essential advantage: a 55% increase in energy efficiency
and 62% latency improvement to 7.0Tb/s/W through circuit switching.
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19. 5. U.S. DoD dilemma
DSN (Defense Switched Network),
DRSN (Defense Red Switched Network),
DVS (DISN VIDEO).
JWICS (Joint Worldwide Intelligence Communications System)
AFSCN (Air Force Satellite Control Network),
NIPRNet (Non-classified Internet Protocol Router Network)
SIPRNet (Secret Internet Protocol Router Network)
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20. “Joint Vision 2010” (1996): towards AIN
Advanced Intelligent Network (AIN) – Bell Labs: 1984
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21. Defense Switched Network architecture (2011)
SUT=SS7 network under a test 21

22. “Joint Vision 2020” (2006): towards IР protocol
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23. CISCO Multifunction SoftSwitch (MFSS)
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24. Service Control Function and TCAP Server
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25. DISN network: CISCO Wide Area Network SoftSwitch
(WAN SS) and Multifunction SoftSwitch (MFSS) (2012)
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26. The target DISN architecture
Tier0 geographic cluster typically consists of at least three Tier0 SSs.
The distance between the clustered SSs must be planned so that the RTT 40 ms.
Propagation delay 6 microseconds/km: distance between Tier0 1860 miles.
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27. "Red Phone" as a birthmark in the environment of AS-SIP
Secure Terminal;
note slot in front
for Crypto PC Card,
use ISDN telephone
lines 128 Kb/s.
The DRSN architecture

28. 6. “Rostelecom” and import substitution
“Rostelecom” IP/MPLS network - 150 nodes:
Juniper routers T1600 (1,6 Тb/s) and many smaller
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29. Rostelecom challenges
Emergence system 112
SS7 and Intelligent network
SIP or AS-SIP
IMS ?
Universal service vs Broadband access
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30. Conclusion
(1) The telecom strategy - to use packet switching in the edges of the network
and circuit switching at the core of the network.
(2) In the rapid developing field of microelectronics - network-on-a-chip (NoC),
the advantage of CS NoC compared to PS NoC is manifested in the
abundance of products (such as MPEG codec) that surround us in
everyday life.
(3) The Defense Information System Network (DISN) - the United States
Department of Defense communications network, the world's largest
departmental network, is in transition phase from CS to PS, but the
classified Defense Red Switch Network (DRSN) will remain CS based for
an unpredictable time.
Seems both technologies—circuit switching and packet switching—
will coexist for a long time yet.
Thanks! See for detail http://injoit.org 2015 No4
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