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GMPLS networks and optical network testbeds. Malathi Veeraraghavan Professor Charles L. Brown Dept. of Electrical & Computer Engineering University of Virginia mvee@virginia.edu Tutorial at ICACT09 Feb. 2009. GMPLS: Generalized MultiProtocol Label Switched networks

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gmpls networks and optical network testbeds
GMPLS networks and optical network testbeds

Malathi Veeraraghavan

Professor

Charles L. Brown Dept. of Electrical & Computer Engineering

University of Virginia

mvee@virginia.edu

Tutorial at ICACT09

Feb. 2009

GMPLS: Generalized MultiProtocol Label Switched networks

(MPLS, SONET, WDM, SDM, VLAN)

outline
Outline
  • Principles
    • Different types of connection-oriented networks
  • Technologies
    • Single network
    • Internetworking
  • Usage
    • Commercial networks
    • Research & Education Networks (REN)
principles
Principles
  • Types of switches and networks
  • Bandwidth sharing modes
    • TCP in connectionless (IP) networks
    • Immediate-request and book-ahead modes in connection-oriented networks
types of networks
Types of networks

Connection-oriented

how is bandwidth shared on a connectionless packet switched network
How is bandwidth shared on a connectionless packet-switched network?
  • Pre-1988 IP network:
    • Just send data without reservations or any mechanism to adjust rates  congestion collapses!
  • Van Jacobson's 1988 contribution:
    • Added congestion control to TCP
    • Sending TCP adjusts rate
    • Advantages:
      • Proportional fairness
      • High utilization
    • Disadvantages:
      • No rate guarantees
      • No temporal fairness (job seniority)
tcp throughput
TCP throughput
  • B: Throughput in congestion-avoidance phase
  • RTT: Round-trip time
  • b: an ACK is sent every b segments (b is typically 2)
  • p: packet loss rate on path
  • T0: initial retransmission time out in a sequence of retries
  • Effective rate = min (r,B)
  • r: bottleneck link rate
  • Padhye, Firoui, Towsley, Kurose, ACM Sigcomm 98 paper
tcp throughput8
TCP throughput

Case

Input parameters

Mean transfer delay

for a 1GB file (s)

Packet loss rate

Bottleneck link rate

Round-trip delay

Case 1

0.0001

100 Mb/s

0.1ms

82.25

Case 2

5ms

89.45

~21Mbps

Case 3

50ms

396.5

Case 4

1Gbps

0.1ms

8.25

Case 5

5ms

39.6

Case 6

50ms

395.7

Case 7

0.001

100

Mbps

0.1ms

82.93

Case 8

5ms

135.4

Case 9

50ms

1293

Case 10

1Gbps

0.1ms

8.64

Case 11

5ms

129.4

Case 12

50ms

1287

Case 13

0.01

100

Mbps

0.1ms

92.41

Case 14

5ms

471.7

~2Mbps

Case 15

50ms

4417

Case 16

1Gbps

0.1ms

12.43

Case 17

5ms

441.7

Case 18

50ms

4387

bandwidth sharing in circuit networks immediate request mode
Bandwidth sharing in circuit networks(immediate-request mode)
  • Key difference:
    • Admission control
    • Intrinsic to circuit networks: position based mux
  • Send a call setup request:
    • if requested bandwidth is available, it is allocated to the call
    • if not, the call is blocked (rejected)
  • M/G/m/m model:
    • m: number of circuits
erlangb formula

r

m

ua

4

17

117

24.8%

58.2%

84.6%

1

10

100

ErlangB formula

r: offered traffic load in Erlangs

: call arrival rate

1/:mean call holding time

m: number of circuits

Pb: call blocking probability

ub: utilization

For a 1% call blocking probability, i.e., Pb = 0.01

If m is small, high utilization can only be

achieved along with high call blocking probability

bandwidth sharing mechanisms in co networks
Bandwidth sharing mechanismsin CO networks

Needed if per-call

circuit rate is a large

fraction of link capacity

(e.g., 1Gbps circuits on a 10Gbps link, m = 10)

Bandwidth sharing mechanisms

Book-ahead

Immediate-request

call duration specified

unspecified call duration

BA-n/BA-First

VBDS (Varying-Bandwidth Delayed Start)

session-type requests

data-type requests

BA-n

BA-First

Users specify a set of call-initiation time options

Users are given first available timeslot

X. Zhu, Ph.D. Thesis, UVA, http://www.ece.virginia.edu/mv/html-files/students.html

comparison of immediate request ir and book ahead ba schemes
Comparison of Immediate-Request (IR) and Book-Ahead (BA) schemes
  • Example
    • To achieve a 90% utilizationwith a call blocking probability less than 10%
      • BA-First schemes are needed when m < 59
    • To achieve a 90% utilization with a call blocking probabilityless than 20%
      • BA-First schemes are needed when m < 32

U: utilization

K: number of time periods in advance-reservation window

m=10, K=10, U = 80%: PB = 0.4%

BA

m=10, U = 80%: PB = 23.6%

m=100, U = 80%: PB= 0.4%

IR

virtual circuit vc networks
Virtual circuit (VC) networks

Call Admission Control

Bandwidth sharing more complex, but better utilization PLUS service guarantees

Needed in circuit networks

Scheduling

(example: weighted fair queueing)

Traffic shaping/policing

(example: leaky-bucket algorithm)

Two additional dimensions

in VC networks

outline14
Outline
  • Principles
    • Different types of connection-oriented networks
  • Technologies
    • Single network
    • Internetworking
  • Usage
    • Commercial networks
    • Research & Education Networks (REN)
technologies
Technologies
  • GMPLS networks
    • Data-(user-) plane protocols
      • packet-switched: MPLS, VLAN Ethernet
      • circuit-switched: SONET/SDH, WDM, SDM (space div. mux)
    • Control-plane protocols:
      • RSVP-TE: signaling protocol
      • OSPF-TE: routing protocol
      • LMP: link management protocol
  • Internetworking
    • GFP, VCAT, LCAS for SONET/SDH
    • PWE3 for MPLS networks
    • Digital wrapper for OTN
multiprotocol label switching mpls

Label Value

CoS

S

TTL

20 Bits

3

1

8

Multiprotocol label switching (MPLS)
  • MPLS Header:
    • Label Value: Label used to identify the virtual circuit
    • Class of Service (CoS): Experimental field, Used for QoS support
    • S: Identifies the bottom of the label stack
    • TTL: Time-To-Live value
  • Virtual circuits: Label Switched Path (LSP)

MPLS Header

ieee 802 1q ethernet vlan
IEEE 802.1Q Ethernet VLAN

new fields

Type/Len

Dest. MAC Address

Source MAC Address

TPID

TCI

Data

FCS

FCS: Frame

Check

Sequence

VLAN Tag

User

Priority

802.1Q Tag Type

CFI

VLAN ID

2 Bytes

3 Bits

1 Bit

12 Bits

vlan tag fields
VLAN Tag Fields
  • Tag Protocol Identifier (TPID)
    • 802.1Q Tag Protocol Type – set to 0x8100 to identify the frame as a tagged frame
  • Tag Control Information (TCI)
    • User Priority
      • As defined in 802.1p, 3 bits represent eight priority levels
    • CFI
      • Canonical Format Indicator, set to indicate the presence of an Embedded-RIF
    • VLAN ID
      • Uniquely identifies the frame's VLAN
sonet sdh rates number is the multiplier
SONET/SDH rates(number is the multiplier)

Example: STS-48 frame has 48 x 90 columns in 125 s

STS-1: 90 columns by 9 rows in 125s

Tanenbaum

optical transport networks otn
Optical transport networks (OTN)
  • G. 872 layers
    • OTS: Optical Transmission Section
    • OMS: Optical Multiplex Section
    • OCh: Optical Channel
  • G.709:
    • Technique for mapping client signals onto the Optical Channel via layers:
      • OTU: Optical Channel Transport Unit, and
      • ODU: Optical Channel Data Unit
layers within an otn
Layers within an OTN

Courtesy: T. Walker's tutorial

otn hierarchy
OTN Hierarchy
  • Electrical domain:
    • OTU: Optical Channel Transport Unit
    • ODU: Optical Channel Data Unit
    • OPU: Optical Channel Payload Unit

Low layer

Higher layers

Courtesy: T. Walker's tutorial

g 709 optical channel frame structure digital wrapper
G. 709 Optical Channel frame structure (digital wrapper)
  • Optical channel (OCh) overhead: support operations, administration, and maintenance functions
  • OCh payload: can be STM-N, ATM, IP, Ethernet, GFP frames, OTN ODUk, etc.
  • FEC: Reed-Solomon RS(255, 239) code recommended; roughly introduces a 6.7% overhead
  • Frame size: 4 rows of 4080 bytes
  • Frame period:
    • OTU1 – 48.971 μs (payload data rate: roughly 2.488 Gbps )
    • OTU2 – 12.191 μs (payload data rate: roughly 9.995 Gbps )
    • OTU3 – 3.035 μs (payload data rate: roughly 40.15 Gbps )

OCh overhead

OCh payload

FEC

technologies24
Technologies
  • GMPLS networks
    • Data-(user-) plane protocols
      • packet-switched: MPLS, VLAN Ethernet, Intserv IP
      • circuit-switched: SONET/SDH, WDM, SDM
    • Control-plane protocols:
      • RSVP-TE: signaling protocol
      • OSPF-TE: routing protocol
      • LMP: link management protocol
  • Internetworking
    • GFP, VCAT, LCAS for SONET/SDH
    • PWE3 for MPLS networks
    • Digital wrapper for OTN
the evolution of resource reservation protocol rsvp
The evolution ofResource reSerVation Protocol (RSVP)
  • RSVP (RFC2205, 1997)
  • RSVP-TE (RFC 3209, 2001)
  • RSVP-TE GMPLS Extension (RFC 3471, 3473, 2003)
  • RSVP-TE GMPLS Extension for SONET/SDH (RFC 3946, 2004, RFC 4606, 2006)
purpose of signaling needed only in co networks
Purpose of signaling(needed only in CO networks)
  • Functions:
    • Call setup:
      • Route selection
      • Admission control: sufficient bandwidth?
      • Switch fabric configuration of each switch
        • recall position based multiplexing
    • Call release
      • release bandwidth for use by others
circuit switched networks phase 1 routing protocol exchanges routing table precomputation

Dest.

Next hop

III-B

III-B

III-C

III-C

Dest.

Next hop

III-*

III

Circuit-switched networksPhase 1:Routing protocol exchanges + routing table precomputation
  • Routing protocols exchange:
    • topology
    • address reachability
    • loading conditions

II

Host I-A

Host III-B

I

III

IV

Host III-C

Dest.

Next hop

V

III-*

IV

circuit switched networks phase 2 signaling for call setup

a

b

d

c

Circuit-switched networksPhase 2: Signaling for call setup

Connection setup actions at each switch on the path:

  • Parse message to extract parameter values
  • Lookup routing table for next hop to reach destination
  • Read and update CAC (Connection Admission Control) table
  • Select timeslots on output port
  • Configure switch fabric: write entry into timeslot mapping table
  • Construct setup message to send to next hop

Connection setup (Dest: III-B;

BW: OC1;

Timeslot: a, 1)

II

b

Host I-A

a

III

I

Host III-B

c

b

c

V

IV

a

d

Dest.

Next hop

Routing

table

III-*

IV

circuit switched networks phase 2 signaling for call setup29

a

b

d

c

Circuit-switched networksPhase 2: Signaling for call setup

Connection setup actions at each switch on the path:

  • Parse message to extract parameter values
  • Lookup routing table for next hop to reach destination
  • Read and update CAC (Connection Admission Control) table
  • Select timeslots on output port
  • Configure switch fabric: write entry into timeslot mapping table
  • Construct setup message to send to next hop

Connection setup (Dest: III-B;

BW: OC1;

Timeslot: a, 1)

II

b

Host I-A

a

III

I

Connection setup

Host III-B

c

b

c

V

IV

a

d

Dest.

Next hop

Routing

table

III-*

IV

Interface (Port);

Capacity; Avail timeslots

CAC

table

Next hop

c; OC12; 1, 4, 5

IV

INPUT

Port /Timeslot

OUTPUT

Port/Timeslot

Timeslot

mapping table

a/1

c/1

Update to remove timeslot 1

from available list

circuit switched networks phase 2 signaling for call setup30

a

b

d

c

Circuit-switched networksPhase 2: Signaling for call setup

II

b

Host I-A

a

Connection setup

III

I

Host III-B

c

b

c

V

IV

a

Connection setup

(Dest: III-B;

BW: OC1;

Timeslot: a, 1)

d

INPUT

Port /Timeslot

OUTPUT

Port/Timeslot

Time slot

could be different

on each hop

a/1

c/2

Perform same set of 6 connection setup steps at switch IV

write timeslot mapping table entry, update CAC table and

send connection setup message to the next hop

circuit switched networks phase 2 signaling for call setup31

a

b

d

c

Circuit-switched networksPhase 2: Signaling for call setup

INPUT

Port /Timeslot

OUTPUT

Port/Timeslot

II

d/2

b/1

b

Host I-A

a

Connection setup

III

I

Host III-B

c

b

c

V

IV

a

Connection

setup

d

Circuit setup

complete

Perform same set of 6 connection setup steps at switch III

Reverse setup-confirmation messages typically sent from destination through switches to source host

circuit switched networks phase 3 user data flow
Circuit-switched networksPhase 3: User-data flow
  • Bits arriving at switch I on time slot 1 at port a are switched to time slot 1 of port c

IN

Port /Timeslot

OUT

Port/Timeslot

1

2

II

d/2

b/1

b

1

2

1

2

a

Host I-A

a

III

I

Host III-B

b

c

b

d

c

c

1

2

IV

a

d

V

IN

Port /Timeslot

OUT

Port/Timeslot

IN

Port /Timeslot

OUT

Port/Timeslot

a/1

c/1

a/1

c/2

release procedure
Release procedure
  • When a communication session ends, there is a hop-by-hop release procedure (similar to the setup procedure) to release timeslots/wavelengths for use by new calls
rsvp messages and parameters
RSVP messages and parameters
  • Messages:
    • Setup: Path (forward) and Resv (reverse)
    • Release: PathTear, ResvTear
  • Parameters
    • Destination: SESSION object
    • Bandwidth: Sender Tspec object or SONET/SDH Tspec
    • Timeslot/Wavelength:
      • Generalized LABEL for ports, wavelengths
      • SUKLM label for SONET/SDH
  • Only supports immediate-request circuits/virtual circuits
    • No time-dimension parameters for book-ahead
explicit route object ero
Explicit Route Object (ERO)
  • A list of groups of nodes along the explicit route (generically called "source route")
  • Thinking: source routing is better for calls than hop-by-hop routing as it can take into account loading conditions
  • Constrained shortest path first (CSPF) algorithm executed at the first node to compute end-to-end route, which is included in the ERO
control plane message transport inband or out of band
Control-plane message transport: inband or out-of-band
  • Separation of control plane from data plane in GMPLS networks - out-of-band

Internet

IP router

IP router

Control-plane messages

Ethernet control ports

GMPLS Network

Ethernet control ports

Circuit

established

SONET

or WDM switch

SONET

or WDM switch

Data-plane link

interface id field
Interface ID field
  • Control plane separation:
    • Requires upstream switch to identify on which data-plane interface the virtual circuit should be routed
    • Interface ID field defined in the tag-length-value format
    • Embedded within the RSVP-HOP object
    • Carried in PATH messages
technologies38
Technologies
  • GMPLS networks
    • Data-(user-) plane protocols
      • packet-switched: MPLS, VLAN Ethernet, Intserv IP
      • circuit-switched: SONET/SDH, WDM, SDM
    • Control-plane protocols:
      • RSVP-TE: signaling protocol
      • OSPF-TE: routing protocol
      • LMP: link management protocol
  • Internetworking
    • GFP, VCAT, LCAS for SONET/SDH
    • PWE3 for MPLS networks
    • Digital wrapper for OTN
ospf te open shortest path first traffic engineering
OSPF-TE: Open Shortest Path First -Traffic Engineering
  • To advertise loading conditions
  • New parameters:
    • Maximum bandwidth of a link
    • Maximum reservable bandwidth: can be greater than the maximum bandwidth to support oversubscription
    • Unreserved bandwidth
  • RFC 3630 - for MPLS networks
  • Only supports immediate-request circuits/virtual circuits
    • No time-dimension parameters for book-ahead
ospf te extensions for gmpls
OSPF-TE extensions for GMPLS
  • RFC 4202 and 4203
  • Main new parameters
    • Shared Risk Link Group
    • Interface Switching Capability Descriptor (ISCD)
      • Allows multiple types of switching techniques
      • Example for SONET: Minimum LSP Bandwidth: OC1 on a SONET interface if the switch demultiplexes down to OC1 level
difference between labels in mpls and circuit switched gmpls
Difference between labels in MPLS and circuit-switched GMPLS
  • In circuit-switched GMPLS networks, labels are not carried in the data plane
    • Labels in circuit-switched networks identify "position" of data for the circuit - time or wavelength
  • In circuit-switched GMPLS networks, cannot assign labels without associated bandwidth reservation
    • In usage section, we will see the value of this feature in MPLS networks
    • See two applications: traffic engineering, VPLS (addressing benefits)
technologies42
Technologies
  • GMPLS networks
    • Data-(user-) plane protocols
      • packet-switched: MPLS, VLAN Ethernet, Intserv IP
      • circuit-switched: SONET/SDH, WDM, SDM
    • Control-plane protocols:
      • RSVP-TE: signaling protocol
      • OSPF-TE: routing protocol
      • LMP: link management protocol
  • Internetworking
    • GFP, VCAT, LCAS for SONET/SDH
    • PWE3 for MPLS networks
    • Digital wrapper for OTN
lmp procedures
LMP procedures
  • Control channel management
    • Set up and maintain control channels between adjacent nodes
  • Link property correlation
    • Aggregate multiple data links into a TE link
    • Synchronize TE link properties at both ends
  • Link connectivity verification (optional)
    • Data plane discovery; If_Id exchange; physical connectivity verification
  • Fault management (optional)
    • Fault notification and localization

Reference: IETF RFC 4204

control plane security
Control-plane security
  • Need authentication and integrity for all control-plane exchanges
  • Since RSVP, OSPF, LMP run over IP, IPsec is a possible solution
technologies45
Technologies
  • GMPLS networks
    • Data-(user-) plane protocols
      • packet-switched: MPLS, VLAN Ethernet, Intserv IP
      • circuit-switched: SONET/SDH, WDM, SDM
    • Control-plane protocols:
      • RSVP-TE
      • OSPF-TE
      • LMP
  • Internetworking
    • GFP, VCAT, LCAS for SONET/SDH
    • PWE3 for MPLS networks
    • Digital wrapper for OTN
why internetworking
Why internetworking?
  • GMPLS networks do not exist as standalone entities
  • Instead they are part of the Internet:
    • Obvious usage: to interconnect IP routers
    • Newer uses:
      • Commercial: interconnect Ethernet switches in geographically distributed LANs via point-to-point links or VPNs
      • Research & Education networks: connect GbE and 10GbE cards on cluster computers and storage devices to GMPLS networks
obvious usage
Obvious usage
  • Router-to-router circuits and virtual circuits

Internet

IP router

IP router

GMPLS Network

SONET

or WDM switch

SONET

or WDM switch

router to router usage
Router-to-router usage
  • OSPF-enabled usage
    • simply treat MPLS virtual circuit or GMPLS circuit as a link between routers
    • allow routing protocol to include these in routing table computations
  • Data-plane
    • IP over MPLS
    • IP over PPP over SONET
      • Packet-over-SONET (PoS)
newer uses
Newer uses
  • New type of gateway functionality
    • No IP layer involvement
    • Instead Ethernet frames are mapped onto MPLS virtual circuits or GMPLS circuits
      • port mapped
      • VLAN mapped
  • Cisco and Juniper routers support Ethernet over MPLS
  • Sycamore and Ciena SONET switches support Ethernet over GMPLS
ethernet port mapped over mpls
Ethernet port mapped over MPLS
  • Send all Ethernet frames received on ports I and II on to the MPLS LSP
  • MPLS LSP: Pseudo-wire
  • Enterprise can allocate IP addresses from one subnet: Virtual Private LAN Service (VPLS)
  • Explains one use for MPLS virtual circuits with no bandwith allocation

SDM-to-MPLS gateway

SDM-to-MPLS gateway

Internet

IP router/MPLS switch

IP router/MPLS switch

Pseudowire

II

I

MPLS LSP (virtual circuit)

Ethernet switch

Ethernet switch

Mux scheme on pseudowire: Ethernet

Enterprise 2

Enterprise 1

Gateway: interfaces have different MUX schemes

unlike switch, which has same MUX scheme on all links

SDM: Space Division Multiplexing

ethernet vlan mapped over mpls
Ethernet VLAN mapped over MPLS
  • Extract frames carrying a specific VLAN ID tag on Ethernet ports I and II and map only these frames on to the MPLS LSP

VLAN-to-MPLS gateway

Internet

VLAN-to-MPLS gateway

IP router/MPLS switch

IP router/MPLS switch

II

I

MPLS LSP

Ethernet switch

Ethernet switch

Enterprise 2

Enterprise 1

ethernet port or vlan mapped over gmpls circuits
Ethernet port or VLAN mapped over GMPLS circuits

SDM-to-SONET/WDM gateway

SDM-to-SONET/WDM gateway

  • Send all frames or frames matching a given VLAN ID tag from Ethernet ports I and II on to the SONET/SDH/WDM circuit
  • SONET/SDH/WDM switches now have Fast Ethernet/GbE/10GbE interfaces in addition to SONET/SDM or WDM interfaces

SONET or WDM switch

SONET or WDM switch

II

I

SONET/SDH/WDM

circuit

Ethernet switch

Ethernet switch

Enterprise 2

Enterprise 1

commercial services
Commercial services
  • EPL: Ethernet private line: map an Ethernet port to a SONET/SDH circuit
  • Fractional-EPL: Map a GbE port to a lower-rate SONET circuit
    • Pause frames sent from switch to client node if buffer fills up
  • V-EPL: Lower-rate VLAN mapped to an equivalent-rate SONET circuit
  • MetroEthernet Forum: E-Line and E-LAN
  • page 110 of GFP section reference: SONET focused
technology
Technology
  • So what technologies are required for this type of internetworking:
    • mapping Ethernet frames on to MPLS/GMPLS virtual circuit/circuit mapping?
technologies55
Technologies
  • GMPLS networks
    • Data-(user-) plane protocols
      • packet-switched: MPLS, VLAN Ethernet, Intserv IP
      • circuit-switched: SONET/SDH, WDM, SDM
    • Control-plane protocols:
      • RSVP-TE
      • OSPF-TE
      • LMP
  • Internetworking
    • GFP, VCAT, LCAS for SONET/SDH
    • PWE3 for MPLS networks
    • Digital wrapper for OTN
why do we need generic framing procedure gfp
Why do we need Generic Framing Procedure (GFP)?
  • The framing techniques used in other data-link layer protocols have problems
  • For example, IP packets are carried over SONET using PPP/HDLC frames (called PoS)
    • HDLC inserts idle frames because SONET is synchronous it needs a constant flow of frames to avoid losing synchronization
  • But, there is a problem:
    • HDLC uses flags for frame delineation. The issue with this framing technique is that if the flag pattern occurs in the payload, an escape byte has to be inserted
    • This causes an increase in the required bandwidth
    • The amount of increase is payload-dependent

page 98 of reference

other framing techniques
Other framing techniques
  • HEC - Header Error Control
    • this is the CRC framing technique used in ATM
    • "A header CRC hunting mechanism is employed by the receiver to extract the ATM cells from the bit/byte synchronous stream. The HEC location is fixed and ATM cell length is fixed. Starting from the assumed cell boundary, the ATM receiver compares its computed HEC value for the assumed ATM cell header against the HEC value indicated by the assumed HEC field. Cell stream delineation is declared after positive validations of the incoming HEC fields of a few consecutive ATM cells."
  • ATM cells are fixed in length, but Ethernet frames are variable-length
  • Therefore, we need a length field in order to implement this HEC-based frame delineation mechanism
  • pages 96-97 of reference
main features of the gfp protocol
Main features of the GFP protocol
  • Common aspects (applicable to all client signals):
    • HEC + Length based delineation
      • Core header has payload length and HEC
    • Error control: error detection
      • Payload type HEC, payload Frame Check Sequence (CRC-32)
    • Multiplexing: linear and ring extension headers
    • Idle frames are sent to maintain synchronization as in HDLC
    • Scrambling as in ATM:
      • core header + payload scrambling
    • Client management - client fail signal
  • Client-dependent aspects:
    • Client-specific encapsulation techniques
  • page 68 of reference
inverse multiplexing in vcat
Inverse multiplexing in VCAT

Implementation of VCAT is only required at select nodes (i.e., the edge nodes); not all multiplexers need to support VCAT

Page 82 of reference

link capacity adjustment scheme lcas
Link Capacity Adjustment Scheme (LCAS)
  • LCAS is a mechanism to allow for automatic bandwidth tuning of a virtually concatenated signal
    • The VCAT group of circuits should already be established using a
      • centralized NMS/EMS based procedure, or
      • by a distributed RSVP-TE based procedure
  • Note that bandwidth cannot be increased beyond the aggregate value of the VCAT signal without a GMPLS RSVP or NMS/EMS procedure of circuit setup
link capacity adjustment scheme lcas62
Link Capacity Adjustment Scheme (LCAS)
  • LCAS is a synchronization procedure between the two ends of a VCAT signal
    • Unlike GMPLS RSVP, it is NOT a bandwidth reservation and circuit setup or release procedure
  • LCAS procedures (triggered by GMPLS or NMS/EMS):
    • add or remove a member of a VCAT group
    • renumber the members in a VCAT group
  • Messages are exchanged between the originating and terminating SONET/SDH nodes to execute these LCAS procedures
    • Add member (ChID, GID)
    • Remove member (ChID, GID)
    • Member status
  • Messages are sent in the H4 byte for high-order VCAT
technologies63
Technologies
  • GMPLS networks
    • Data-(user-) plane protocols
      • packet-switched: MPLS, VLAN Ethernet, Intserv IP
      • circuit-switched: SONET/SDH, WDM, SDM
    • Control-plane protocols:
      • RSVP-TE
      • OSPF-TE
      • LMP
  • Internetworking
    • GFP, VCAT, LCAS for SONET/SDH
    • PWE3 for MPLS networks
    • Digital wrapper for OTN
pseudo wire emulation
Pseudo Wire Emulation
  • Pseudo Wire Emulation Edge-to-Edge (PWE3) is a mechanism for emulating certain services across a packet-switched network:
    • Services: Frame-relay, ATM, Ethernet, TDM services, such as SONET/SDH
    • Packet-switched network:
      • IP
      • MPLS
    • Common usage: Ethernet service over MPLS
      • Port-mapped to MPLS LSP
      • VLAN mapped to MPLS LSP
    • IETF RFC 3985
digital wrapper
Digital wrapper
  • ITU-T G. 709 provides a method to carry Ethernet frames, ATM cells, IP datagrams directly on a WDM lightpath
outline66
Outline
  • Principles
    • Different types of connection-oriented networks
  • Technologies
    • Single network
    • Internetworking
  • Usage
    • Commercial networks
    • Research & Education Networks (REN)
commercial uses
Commercial uses
  • Semi-permanent MPLS virtual circuits
    • Traffic engineering
    • Voice over IP
      • QoS concerns: telephony has a 150ms one-way delay requirement (with echo cancellers)
    • Business or service provider interconnect
      • interconnecting geographically distributed campuses of an enterprise
      • interconnecting wide-area routers of an ISP service provider
traffic engineering te
Traffic engineering (TE)
  • Since BGP and OSPF routing protocols mainly spread reachability information, routing tables are such that some links become heavily congested while others are lightly loaded
  • MPLS virtual circuits are used to alleviate this problem
    • e.g., NY to SF traffic could be directed to take an MPLS virtual circuit on a lightly loaded route avoiding all paths on which more local traffic may compete
  • This is an application of MPLS VCs without bandwidth allocation
goals of traffic engineering te
Goals of Traffic Engineering (TE)
  • Monitor network resources and control traffic to maximize performance objectives
    • Goal of TE is to achieve efficient network operation with optimized resource utilization in an Autonomous System
  • Goals of TE can be:
    • Traffic oriented
      • Enhance the QoS of traffic streams
      • Minimization of loss and delay
      • Maximization of throughput
    • Resource oriented
      • Load balancing
      • Minimize maximum congestion or minimize maximum resource utilization
      • Output – decreased packet loss and delay, increased throughput
business or service provider interconnect
Business or service provider interconnect
  • Multiple options:
    • TDM circuits (traditional private line, T1, T3, OC3, OC12, etc.)
    • Ethernet private line
      • point-to-point (Ethernet over MPLS/SONET/WDM)
      • VPNs (called Virtual private LAN service)
    • MPLS VPNs
    • WDM lightpaths
    • Dark fiber
dynamic circuits virtual circuit gmpls control plane
Dynamic circuits/virtual circuit(GMPLS control-plane)
  • Commercial:
    • fast restoration
      • circuit/VC setup delay significant
    • rapid provisioning
      • Verizon: Bandwidth on Demand (Just-in-Time Provisioning)
      • AT&T: Shared mesh networks
        • Customer Applications for dynamic network configuration
          • Key industries: Financial, Media & Entertainment
          • Corporate Utility Backbone Networks (e.g. reconfigure for disaster recovery)
          • Distribution of real-time content (e.g., Video)
      • Level3: Vyvx service
research education g mpls networks
Research & Education(G)MPLS networks
  • Internet2’s Dynamic Circuit network
  • NSF-funded DRAGON
  • DOE's ESnet - Science Data Network
  • DOE's Ultra Science Network (USN)
  • NSF-funded CHEETAH
internet2 dwdm network
Internet2 DWDM network

Infinera

DWDM system

http://events.internet2.edu/speakers/speakers.php?go=people&id=178

Rick Summerhill talk (10/11/2007)

internet2 dynamic circuit dc network
Internet2 Dynamic Circuit (DC) network

Ciena CD-CI

Eth-SONET

switch

http://events.internet2.edu/speakers/speakers.php?go=people&id=178

Rick Summerhill talk (10/11/2007)

internet2 ip routed network
Internet2 IP-routed network

IP-router-to-router links on one wavelength

SONET switch-to-switch links on another wavelength

Ciena CD-CI

Eth-SONET

switch

Juniper

T640 IP router

http://events.internet2.edu/speakers/speakers.php?go=people&id=178

Rick Summerhill talk (10/11/2007)

equipment at each pop
Equipment at each PoP

http://events.internet2.edu/speakers/speakers.php?go=people&id=178

Rick Summerhill talk (10/11/2007)

control plane software for dc network
Control-plane software(for DC network)
  • OSCARS implemented in InterDomain Controller (IDC) - one per domain
    • Abstracted topology exchange
    • Interdomain scheduling
    • Interdomain signaling (for provisioning)
  • DRAGON (intradomain control-plane)
    • Used in Internet2’s DC network
    • Intradomain routing, path computation, signaling (for provisioning)
oscars
OSCARS
  • On-demand Secure Circuits and Advance Reservation System (OSCARS)
  • DOE Office of Science and ESnet project
  • Co-development with Internet2
  • Web Service based provisioning infrastructure, which includes scheduling, AAA architecture using X.509 certificates
    • Extended to include the DICE IDCP
    • Reservations held in SQL database
  • Recall no support for book-ahead in GMPLS control protocols
  • http://www.es.net/oscars/index.html

http://www.csm.ornl.gov/workshops/NetworkingResearchChallenges/agenda.html

Talk by Tom Lehman, Sep. 28, 2008

dragon
DRAGON
  • Washington DC metro-area network:
    • Adva (old Movaz) WDM switches and Ethernet switches (G.709)
  • Control-plane software:
    • Network Aware Resource Broker – NARB
      • Intradomain listener, Path Computation
    • Virtual Label Swapping Router – VLSR
      • Implements OSPF-TE, RSVP-TE
      • Run on control PCs external to switches (since not all switches implement these GMPLS control-plane protocols)
      • Communicates with switches via SNMP, TL1, CLI to configure circuits.
    • Client System Agent – CSA
      • End system software for signaling into network (UNI or peer mode)
    • Application Specific Topology Builder – ASTB
      • User Interface and processing which build topologies on behalf of users
      • Topologies are a user specific configuration of multiple LSPs

http://dragon.east.isi.edu

open source dcn software suite
Open Source DCN Software Suite
  • OSCARS (IDC)
    • Open source project maintained by ESNet and Internet2
    • Uses WDSL, XML, SQL database to store reservations
    • Reservations accepted with 1 minute granularity
  • DRAGON (DC)
    • NSF-funded Open source project maintained by USC ISI EASTand MAX
  • Version 0.4 of DCNSS current deployed release
    • https://wiki.internet2.edu/confluence/display/DCNSS
  • DCN workshops offered for training:
    • http://www.internet2.edu/workshops/dcn/index.html

http://www.csm.ornl.gov/workshops/NetworkingResearchChallenges/agenda.html

Talk by Tom Lehman, Sep. 28, 2008

dice idcp
DICE IDCP
  • Dante, Internet2, CANARIE, ESNet
  • http://www.controlplane.net
  • IDCP: InterDomain Controller Protocol
  • wsdl - web service definition of message types and formats
  • xsd – definition of schemas used for network topology descriptions and path definitions

http://www.csm.ornl.gov/workshops/NetworkingResearchChallenges/agenda.html

Talk by Tom Lehman, Sep. 28, 2008

interdomain controller idc protocol idcp
InterDomain Controller (IDC) Protocol (IDCP)
  • The following organizations have implemented/deployed systems which are compatible with this IDCP
    • Internet2 Dynamic Circuit Network (DCN)
    • ESNet Science Data Network (SDN)
    • GÉANT2 AutoBahn System
    • Nortel (via a wrapper on top of their commercial DRAC System)
    • Surfnet (via use of above Nortel solution)
    • LHCNet (use of I2 DCN Software Suite)
    • Nysernet (use of I2 DCN Software Suite)
    • LEARN (use of I2 DCN Software Suite)
    • LONI (use of I2 DCN Software Suite)
    • Northrop Grumman (use of I2 DCN Software Suite)
    • University of Amsterdam (use of I2 DCN Software Suite)
    • DRAGON Network
  • The following "higher level service applications" have adapted their existing systems to communicate via the user request side of the IDCP:
    • LambdaStation (FermiLab) – CMS project on Large Hadron Collider
    • TeraPaths (Brookhaven) - ATLAS project on Large Hadron Collider
    • Phoebus

http://www.csm.ornl.gov/workshops/NetworkingResearchChallenges/agenda.html

Talk by Tom Lehman, Sep. 28, 2008

heterogeneous network technologies complex end to end paths

Ethernet

Router

SONET Switch

Lambda Switch

Heterogeneous Network TechnologiesComplex End to End Paths

Example: Internet2 DC

Example: DRAGON

Example: ESNet SDN

AS 2

AS 1

IP Control Plane

AS 3

IP Control Plane

IP Control Plane

VLSR

Router MPLS LSP

Ethernet over SONET

VLSR

Ethernet over WDM

End

System

End

System

Ethernet Segment

VLSR Established VLAN

Ethernet Segment

VLSR Established VLAN

http://events.internet2.edu/speakers/speakers.php?go=people&id=178

Rick Summerhill talk (10/11/2007)

idcp operation
IDCP operation

Route selection,

admission control

centralized per domain at IDC

  • Advance reservation request and circuit provisioning at scheduled time:
    • End user signals IDC with a reservation request
    • Authenticate requester and check authorization
    • Request reservation (create time, bandwidth, VLAN tag)
    • Signaling: creation of circuit (automatic or in response to message to IDC)
  • Topology exchange: interdomain (abstracted topology information)
  • Monitoring

http://hpn.east.isi.edu/dice-idcp/dice-idcp-v1.0/idc-protocol-specification-may302008.doc

intra domain operations
Intra-domain operations
  • Using DRAGON in Internet2 DCN
    • NARB does intra-domain path computation after collecting routing information by listening to OSPF-TE exchanges between VLSRs
    • These intradomain paths are provided to IDC for use during resource scheduling (upto 3 path options are considered)
    • 5 VLSRs serve 22 CD-CIs: “subnets of CD-CIs”
    • In Signaling phase, VLSR sends TL1 command to edge CD-CI, which initiates proprietary hop-by-hop signaling to configure circuit through subnet
doe networks
DOE networks
  • ESnet and Science Data Network (SDN)
    • OSCARS: an advance-reservation system
    • Science Data Network: MPLS network
  • UltraScience Network
    • Research network for DoE labs
    • GbE and SONET (Ciena CD-CI)
    • Centralized scheduler for advance-reservation calls
    • 5-PoP network: ORNL, Atlanta, Chicago, Seattle, Sunnyvale
    • Connections to Fermi Lab, PNNL, SLAC, CalTech
  • Lambdastation: CMS project
    • Between Fermi Lab and Univ. of Nebraska
nsf funded cheetah network gbethernet and sonet

GaTech

NSF-funded CHEETAH network GbEthernet and SONET

UVa

TN PoP

CUNY

GbE

SN16000

GbE

NCSU

End hosts

GbE/

10GbE

card

OC192

card

Control

card

GbE

GbEs

OC-192

NC PoP

GA PoP

SN16000

SN16000

GbE

GbE/

10GbE

card

Control

card

OC192

cards

GbE/

10GbE

card

GbE

OC192

card

Control

card

End hosts

End hosts

OC-192

GbE

GbE

ORNL

Sycamore SN16000

SONET switch with GbE/10GbE interfaces

networking software
Networking software
  • Sycamore switch comes with built-in GMPLS control-plane protocols:
    • RSVP-TE and OSPF-TE
  • We developed CHEETAH software for Linux end hosts:
    • circuit-requestor
      • allows users and applications to issue RSVP-TE call setup and release messages asking for dedicated circuits to remote end hosts
    • CircuitTCP (CTCP) code
  • http://www.ece.virginia.edu/cheetah/
cheetah network usage

IP-routed network

SONET circuit-switched network

CHEETAH network usage

End Host

End Host

CHEETAH software

CHEETAH software

DNS client

DNS client

RSVP-TE module

RSVP-TE module

Application

Application

TCP/IP

TCP/IP

NIC 1

Circuit

Gateway

Circuit

Gateway

NIC 1

CTCP/IP

CTCP/IP

NIC 2

NIC 2

  • Bandwidth-sharing mode:
    • Immediate-request mode
    • Heterogeneous rate allocation under high loads:
      • higher BW for large files than for small files
  • Applications:
    • Common file transfers (web, P2P, CDN, storage)
      • attempts circuits for large files (if blocked, use IP-routed path)
      • use IP-routed path for small files
end to end call setup delay measurements
End-to-end call setup delay measurements
  • Delays incurred in setting up a circuit between host zelda1 (in Atlanta, GA) and host wuneng (in Raleigh, NC) across the CHEETAH network
  • Observations:
    • Setup delays for SONET circuits (OC1, OC3) are small (166ms)
    • Setup delays for Ethernet-over-SONET (EoS) hybrid circuits are much higher (1.6s) (no standard; proprietary implementation)
    • Signaling message processing delays dominate end-to-end circuit setup delays
spectrum of services
Spectrum of services

New services

eScience

Leased line

Verizon BoD

IP

10G POTS

  • Book-ahead mode
  • Call duration specified
  • Current solution:
    • centralized per-domain path computation/admission control
  • Low call handling volume
  • Plain Old Telephone Service (64kbps)
  • Immediate-Request (IR) mode
  • Unspecified call duration
  • Low call setup overhead
    • ( holding times can be shorter)
  • Distributed path computation/admission control
  • High call handling volume

OSCARS/DRAGON

CHEETAH

summary
Summary
  • Principles
    • Different types of connection-oriented networks
  • Technologies
    • Single network: MPLS, SONET, OTN
    • Internetworking: PWE3, GFP, G.709
  • Usage
    • Commercial networks
    • Research & Education Networks (REN)
references on bandwidth sharing modes
References on bandwidth sharing modes
  • X. Fang and M. Veeraraghavan, “On using a hybrid architecture for file transfers,” acceptedto IEEE Transactions on Parallel and Distributed Systems, 2009.
  • X. Zhu and M. Veeraraghavan, "Analysis and Design of Book-ahead Bandwidth-Sharing Mechanisms," IEEE Transactions on Communications, Dec. 08.
  • X. Fang and M. Veeraraghavan, On using circuit-switched networks for file transfers,” in IEEE Globecom, New Orleans, LA, Nov. 2008.
  • X. Zhu, M. E. McGinley, T. Li, and M. Veeraraghavan, "An Analytical Model for a Book-ahead Bandwidth Scheduler," in IEEEGlobecom Washington, DC, Nov. 2007.
  • X. Zhu, X. Zheng, and M. Veeraraghavan, "Experiences in implementing an experimental wide-area GMPLS network,"IEEE Journal on Selected Areas in Communications (JSAC), Apr. 2007.
  • M. Veeraraghavan, X. Fang, and X. Zheng, “On the suitability of applications for GMPLS networks,” in IEEE Globecom, San Francisco, CA, Nov. 2006.
references for otn
References for OTN
  • ITU-T G. 872 and G.709/Y.1331 Specifications
  • T. Walker, “Optical Transport Network (OTN) Tutorial”, Available online: http://www.itu.int/ITU-T/studygroups/com15/otn/OTNtutorial.pdf
  • Agilent, “An overview of ITU-T G.709,” Application Note 1379
  • P. Bonenfant and A. Rodriguez-Moral, "Optical Data Networking," IEEE Communications Magazine, Mar. 2000, pp. 63-70.
  • E. L. Varma, S. Sankaranarayanan, G. Newsome, Z.-W. Lin, and H. Esptein, “Architecting the Services Optical Network,” IEEE Communications Magazine, Sept. 2001, pp. 80-87.
references for ospf te
References for OSPF-TE
  • RFC 2702 - Requirements for Traffic Engineering Over MPLS: http://www.faqs.org/rfcs/rfc2702.html
  • RFC 3630 - Traffic Engineering (TE) Extensions to OSPF Version 2: http://www.faqs.org/rfcs/rfc3630.html
  • RFC 4203 - OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS) : http://www.ietf.org/rfc/rfc4203.txt
  • RFC 2328 - OSPF Version 2 : http://www.ietf.org/rfc/rfc2328.txt
  • OSPFv2 Routing Protocols Extensions for ASON Routing: http://www.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-ason-routing-ospf-02.txt
  • RFC 4202 - Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS): http://www.ietf.org/rfc/rfc4202.txt
  • RFC 3471- Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description: http://www.faqs.org/rfcs/rfc3471.html
  • Dimitri Papadimitriou, IETFInternet Draft, "OSPFv2 Routing Protocols Extensions for ASON Routing," draft-ietf-ccamp-gmpls-ason-routing-ospf-02.txt, October 2006.
reference for gfp vcat lcas
Reference for GFP/VCAT/LCAS
  • IEEE Communications Magazine, May 2002, Special issue on "Generic Framing Procedure (GFP) and Data over SONET/SDH and OTN," Guest Editors, Tim Armstrong and Steven S. Gorshe
  • 6 excellent papers
references for ren projects
References for REN projects
  • IEEE Communication Magazine special issue, March 2006
    • DRAGON, UltraScience Net, CHEETAH, several other projects