Large-Scale WAN Design 0501_11 F 8_c 1 NW

Large-Scale WAN Design 0501_11 F 8_c 1 NW 97_EMEA_111 1

Business Requirements • Cost reduction Voice and data consolidation • Maximize network control Manage SP Service Agreements Build Private network • Increase efficiency You pay for BW in the WAN, use it right 0501_11 F 8_c 1 NW 97_EMEA_111 2

Traffic PBX Data Voice Video • Interactive • File transfer • Multiprotocol • http: //www • Interoffice PBX • Fax • Modem • Quality • Distance learning • Teleconferencing • Multicast • Quality 0501_11 F 8_c 1 NW 97_EMEA_111 3

Traffic Mix Spectrum 100%Data 100%Voice IP over Services Mix ATM (cell) IP FR TDM ATM LL FR PPP Real-Time Apps WEB interactive SNA Non Real-Time Apps FTP 0501_11 F 8_c 1 NW 97_EMEA_111 Voice Video FAX Call Center Voicemail store/forward FAX 4

Bandwidth in the Wide Area POS ATM Frame Relay Leased Line X. 25 9. 6 K 56/64 K E 1/T 1 E 3/T 3 OC 12 OC 192 Your Options Will Vary 0501_11 F 8_c 1 NW 97_EMEA_111 5

Public vs. Private Networking Where the Services are Performed Public Hybrid Private CPE Switch/Router CPE CPE Public Basic 0501_11 F 8_c 1 NW 97_EMEA_111 CPE Hybrid (Public Value Added) CPE Private 6

Switch/Router Public WAN CPE • Customer owned CPE PBX Campus Public PSTN • Switching in cloud • Services Internet The Internet (IP) Public ATM Frame Relay X. 25 service PSTN • Statistically shared network infrastructure 0501_11 F 8_c 1 NW 97_EMEA_111 7

Switch/Router Public: Hub and Spoke Design CPE Frame Relay, X. 25 Service, PSTN and ISDN Frame Relay or X. 25 Cost-Medium Low PSTN / ISDN Cost-Usage Based • Low cost of bandwidth • Readily available • Low cost of management • Flexible topology • Reliability and availability provided by the network 0501_11 F 8_c 1 NW 97_EMEA_111 8

Switch/Router Public: ATM CPE PBX ATM PBX Cost High, Expected to Fall • Variable bandwidth-T 1/E 1 and above • Guaranteed Qo. S • Reliability and availability provided by network 0501_11 F 8_c 1 NW 97_EMEA_111 9

CPE Private WAN CPE PBX Campus CPE • Customer owns cloud, rents wire/fibre only • CPE Switching Wire/Fibre • Connection Services Leased Lines Dark Fiber Satellite • Own network infrastructure 0501_11 F 8_c 1 NW 97_EMEA_111 10

CPE Private: Router Network Leased Lines CPE Cost- Fixed, High • Predictable bandwidth • Good control over delay • Management and deployment costs 0501_11 F 8_c 1 NW 97_EMEA_111 11

CPE Private: Switch Network Cell, Frame Relay or X. 25 CPE Campus PBX Cost- Fixed Monthly, High Cost of Ownership, Save on PSTN Charges • Very predictable bandwidth • High control over delay • Scalability needs SVCs • Management and deployment costs 0501_11 F 8_c 1 NW 97_EMEA_111 12

Hybrid WAN (Public Value Add) • Cloud extends to CPE PBX Campus • Services Managed services Internet Virtual Private Network • Network appears as private network • Statistically allocated BW 0501_11 F 8_c 1 NW 97_EMEA_111 13

Hybrid: SP Managed Services PBX Campus • SP Services SVCs, Reliability, Availability Configs, Reporting, Maintenance • Enterprise provides Security (encryption, L 2 TP, AAA) RSVP Cost -Varies (Competition), Decrease Costs - Consolidate Voice 0501_11 F 8_c 1 NW 97_EMEA_111 14

Hybrid: Public Internet—VPN Internet Basic Cost- Fixed, Low Enhanced Cost- Fixed, Plus QOS Premium • Variable bandwidth • Predictable bandwidth, delay • Variable delay • QOS w/CAR (IP precedence) • Requires high levels of security 0501_11 F 8_c 1 NW 97_EMEA_111 15

CPE Hybrid: Public ATM CPE • Same as Basic Services PBX ATM IWF Frame Relay IWF PSTN/ISDN • Service (voice)Interworking between FR, PSTN (IWF) • SVC services Cost - Medium / High, but Save on Long Haul PSTN 0501_11 F 8_c 1 NW 97_EMEA_111 • Reliability and availability provided by the network 16

Inherent WAN Network Features Public Private Hybrid Recurring Costs Wire Buy equip People cost High Recurring costs +enhancements Equipment Low High Low Wire High Low High but Bundled Low High Lowest BW control by SP Uncertain availability shared by large customer base 100 your BW 99. 9 availability control all traffic Service agreement enforcement req’d Cost Control 0501_11 F 8_c 1 NW 97_EMEA_111 17

WAN Hierarchical Design Layer 3 WAN Layer 2 WAN Branch Mobile Branch SOHO FRAD Branch SOHO WAN Core Public Branch ATM, T 3/E 3, T 1/E 1 SOHO Distribution Branch Mobile Access 0501_11 F 8_c 1 NW 97_EMEA_111 Distribution Branch FRAD Branch Access 18

Router-Based WAN • Multiprotocol (L 3) IP, IPX, AT, DEC, etc. Branch Mobile SOHO • Data mostly Branch Client/server Legacy IBM SOHO Public SOHO Web traffic • Some voice (emerging) WAN Core Branch Distribution Mobile Access Vo. IP, Vo. FR 0501_11 F 8_c 1 NW 97_EMEA_111 19

Router WAN Core • Public net connections Frame Relay, ATM, Leased, X. 25 • Full/partial mesh Public FR, ATM, Leased Redundancy, BW +, robust • Efficient feature use Use fastest switching path Mesh Formula: n x (n-1) 2 0501_11 F 8_c 1 NW 97_EMEA_111 20

Distribution to Core Connection • Redundant connect Distribution Separate COs, parallelism • Route summarization OSPF WAN Core • Separate areas/AS • SAP filtering 0501_11 F 8_c 1 NW 97_EMEA_111 21

Distribution to Access Connection Access • Branch connection Distribution Branch Frame, leased, ISDN, X. 25 Permanent backup Mobile Core • Small/home office ISDN, Frame, X. 25, Dial SOHO Dial backup, analog phone • Mobile Branch PPP, DHCP, security 0501_11 F 8_c 1 NW 97_EMEA_111 22

Router WAN Considerations • Layer 3 addressing • Routing protocols • Backup/redundancy • Provisioning public services • Scalability • Features 0501_11 F 8_c 1 NW 97_EMEA_111 23

Routing Protocols: OSPF • Good for partial mesh NBMA networks Too many link-state updates in full mesh • OSPF guidelines: Routers per area: 40– 50 Use of STUB areas: external routes not advertised Use of NSSA: allows limited external route import OSPF on-demand circuit (rfc 1793): reachability presumed For ISDN, X. 25 SVCs, and dialup-->usage sensitive 0501_11 F 8_c 1 NW 97_EMEA_111 24

Switched-Based WAN • Multiservice (Layer 2) Branch FRAD ATM, Frame Relay (interworking), Branch X. 25, voice, circuit switching (TDM replacement) • Traffic consolidation Data, voice, video, • Private network Reduce costs, increase control and flexibility, better quality, security, and availability 0501_11 F 8_c 1 NW 97_EMEA_111 FRAD Branch WAN Core Branch ATM, T 3/E 3, T 1/E 1 Distribution Branch Access FRAD Branch 25

Switched WAN Core ATM, T 3/E 3, T 1/E 1 • Full/partial mesh Redundancy, increased BW • Know traffic patterns Will traffic take preferred paths • Trunk speeds and feeds Size in fail-over capacity 0501_11 F 8_c 1 NW 97_EMEA_111 26

Core to Distribution Connection Distribution • Extends switch core Scalability, connectivity • Redundant connections Core Use separate CO facilities 0501_11 F 8_c 1 NW 97_EMEA_111 27

Distribution to Access Connection • Frame Relay UNI PBX Public Frame Relay 3174 Trunk PBX • Circuit switch I/F PBX (voice) and Circuit emulation 0501_11 F 8_c 1 NW 97_EMEA_111 Distribution Core 3800 • Frame Relay trunk Remote Switch concentrator FR UNI FRAD, router • Frame Relay NNI Access PBX DACS CSU FR NNI FR PBX FR UNI (FF) X. 25 28

Multiservice Network ATM Crop. Data Network OC-3 PBX DS 3 • Voice, data, and video services Major sites, dispersed HQ • Quality of service ATM, Opti. Class DS 3 PBX OC-3 DS 3 ATM DS 1 DS 3 DS 1 PBX OC-3 DS 1 DS 3 PBX OC-3 DS 3 OC-3 DS 1 PBX OC-3 • Congestion control 0501_11 F 8_c 1 NW 97_EMEA_111 Fore. Sight 29

Trends: Consolidation Public Voice Private Line Voice and Data PBX PSTN or VPN PBX T 1 Public Data PSTN or VPN Decreasing Total Cost Need for Speed Consolidation/ Need for Qo. S/Co. S Maximization Multiservice Carrier Network Private Line Narrowband ATM Broadband ATM 0501_11 F 8_c 1 NW 97_EMEA_111 30