2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 1 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 1 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 1Cisco Confidential 1 2010 Cisco and/or its affiliates. All rights reserved.

Vodafone Romania ITP Knowledge Transfer

Refresh Routing = building maps and giving directions Switching = moving packets between interfaces Routers are packet switches Path determination is overhead

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IPv4: Internet Protocol, version 4. The protocol that glues the Internet together. Provides (unreliable) packet delivery service for TCP, UDP, ICMP, IGMP.

IPv6: Internet Protocol, version 6.128 bits address, newer version of Internet Protocol.Will it ever happen?

UNIX Host UNIX HostInternetTCP/IP

32 BitsNetwork Host

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Company A Company B

Unique addressing allows communication between end stations Path choice is based on location Location is represented by an IP address

Hardware state Static

Routes are manually defined Dynamic

Routes are learned from a protocolRouting protocol updates are exchanged by routers to learn about paths to other logical networksEach routing protocol offers features that can make it desirable as part of an internetwork design

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Each routing protocol offers features that can make it desirable as part of an internetwork design

I Know About:Network XNetwork YNetwork Z

I Know About:Network ANetwork BNetwork CA

BC

XYZ

Routing Update

Exchanges Network Knowledge

NameNameRIPRIP

TypeTypeDVDV

ProprietaryProprietaryNoNo

FunctionFunctionInteriorInterior

UpdatesUpdates30 Sec30 Sec

MetricMetricHopsHops

VLSMVLSMNoNo

SummSummAutoAuto

IP routing protocols are characterized as

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RIPRIPRIPv2RIPv2IGRPIGRPEIGRPEIGRPOSPFOSPFISIS--ISISBGPBGP

DVDVDVDVDVDV

Adv DVAdv DVLSLSLSLSDVDV

NoNoNoNoYesYesYesYesNoNoNoNoNoNo

InteriorInteriorInteriorInteriorInteriorInteriorInteriorInteriorInteriorInteriorInt/ExtInt/ExtExteriorExterior

30 Sec30 Sec30 Sec30 Sec90 Sec90 SecTrigTrigTrigTrigTrigTrigTrigTrig

HopsHopsHopsHopsCompCompCompCompCostCostCostCostN/N/AA

NoNoYesYesNoNoYesYesYesYesYesYesN/AN/A

AutoAutoAutoAutoAutoAutoBothBothManManAutoAutoManMan

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TCP: transmission control protocolconnection-oriented, reliable, full duplex, byte stream service

UDP: User datagram protocolConnectionless, unreliable

SCTP: Newest transport protocol coming out from IETF and can

TCP/UDP/SCTP protocols:

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SCTP: Newest transport protocol coming out from IETF and can be seen as enhanced TCP adding some important features to TCP and being design for real-time signaling transport over IP.

Unreliable and unordered datagram service Adds multiplexing No flow control Endpoints identified by ports

servers have well-known ports

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servers have well-known ports Header format

Optional checksumpsuedo header + UDP header + data

SrcPort DstPortChecksum Length

Data

0 16 31

TCP travels in IP datagrams Internet routers only look at IP header to forward

datagrams TCP at destination interprets TCP messages

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SrcPort DstPortSequenceNum

Acknowledgment

0 4 10 16 31

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Options (variable)

Data

Checksum

HdrLen 0 Flags

UrgPtr

AdvertisedWindow

Keep upper layers (TCAP, SCCP, ISUP) and use IP transport Transparent to ALL current SS7 end-devices Maintain reliability of SS7 (mimic/support MTP layers) Preserve the upper layer timers STANDARDS = Sigtran IETF (Internet Engineering Task Force)

This we will discuss later ..in SCTP Section

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This we will discuss later ..in SCTP Section

Services/Features SCTP TCPConnection-oriented Yes YesReliable data transfer Yes YesUnordered data delivery Yes NoFlow control Yes YesCongestion control Yes Yes

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Congestion control Yes YesSelective ACKs Yes OptionalPreservation of message boundaries Yes NoMultistreaming Yes NoMultihoming Yes NoProtection against SYN flooding attacks Yes NoPsuedo-header for checksum No (uses vtags) Yes

ASSOCIATION ASSOCIATION STARTUP & STARTUP &

SEQUENCED DELIVERY WITHIN STREAMSSEQUENCED DELIVERY WITHIN STREAMSNo of Streams/AssociationNo of Streams/Association

USER DATA FRAGMENTATIONUSER DATA FRAGMENTATIONFragmentation to conforms to Path Fragmentation to conforms to Path MTUMTU

ACKNOWLEDGEMENT AND CONGESTION AVOIDANCEACKNOWLEDGEMENT AND CONGESTION AVOIDANCE

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STARTUP & STARTUP & TAKEDOWNTAKEDOWN

SCTP User Initiate, SCTP User Initiate, Association, CookieAssociation, Cookie

ACKNOWLEDGEMENT AND CONGESTION AVOIDANCEACKNOWLEDGEMENT AND CONGESTION AVOIDANCETransmission Sequence Number (Transmission Sequence Number (TSNTSN))

CHUNK BUNDLINGCHUNK BUNDLINGChunk Bundles with Common HeadersChunk Bundles with Common Headers

PACKET VALIDATIONPACKET VALIDATION32 Bit Checksum (Alder32 Bit Checksum (Alder--32)32)

PATH MANAGEMENTPATH MANAGEMENTHeartbeat, Choosing the correct Path for Outgoing Packets Heartbeat, Choosing the correct Path for Outgoing Packets

How these fits in the OSI Model

Telnet FTP SMTP HTTP FingerSNMPNTPNNTP M2PA

Presentation

Application XUA

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Copper Cable

IP

Radio WavesFiber Optic strand

Ethernet PPPFDDIToken-Ring

TCPICMP

UDP

SLIP

Physical

Session

Transport

Network

DatalinkARP

SCTP

Thank you.Thank you.