Gigabit Ethernet Vs Asynchronous Transfer Mode John A

Gigabit Ethernet Vs Asynchronous Transfer Mode John A. Clark Bay Networks Technical Account Manager John. Clark@Anixter. Com

Not a Desktop Debate • Industry analysis shows 10/100 Ethernet is the clear choice for the desktop technology • Token Ring important in vertical markets • ATM to-the-desk for niche applications

Not a Protocol Debate LAN Protocol Breakdown 80% 70% 60% 50% 40% 30% 20% 10% 0% IP 1994 IP 1996 1998 E SNA IPX Source: Gartner Group 3/97 2000 E Others 2002 E Net. BEUI • IP has emerged as the protocol of choice most organisations have a migration plan • Few networks are IP only - other protocols e. g. IPX, Net. BEUI, SNA are still important on existing LANs

It’s a Backbone Issue What Technology/Business Factors Should be Considered? • • Network Speed/distance Standards Status Network Resilience Routing/Layer 3 switching Supported Applications Network Management Investment/Ease of Use

Network Speed/Distance Gigabit Ethernet • 1000 Base. CX: 25 m copper • 1000 Base. SX: 550 m on 50 micron MM fibre, 220 m on 62. 5 micron (DMD) • 1000 Base. LX: 550 m all MM fibre , 3 km SM fibre - Long reach 50 km proprietary • 1 Gbps limit - 10 Gbps ? • 200 m network diameter restrictions - CSMA/CD as shared media • • • ATM 25 Mbps Cat V UTP 155 Mbps - OC/3 fibre 622 Mbps - OC/12 fibre 800+m on MM, 15 km on SM 2. 4 Gbps - OC/48, 10 Gbps OC/192. . . no theoretical limit • DWDM - multiple OC/192 • ATM/SDH WAN (e. g. BT Cellstream) • No max network diameter

Standards Status Gigabit Ethernet • 802. 3 z OK • 802. 3 ab 1000 base. T tba • 802. 3 x flow control • 802. 1 P priority OK • 802. 1 Q VLAN tag OK • RSVP, RTP…Diffserv tba ATM • Anchorage Accord combined standard • IISP • PNNI OK • LANE 2. 0 OK • MPOA 1. 0 OK • NHRP OK

Network Resilience Gigabit Ethernet ATM • Proprietary H/W or Spanning Tree • ST stability /convergence issues? • No standards based load -sharing -proprietary MLT • Use of OSPF / RIP with Layer 3 switching • Inherently highly redundant technology • Standards based NNI • Parallel load-sharing links for resilience & aggregate bandwidth • Highly meshed topologies - PNNI multi peer groups

Routing/Layer 3 Switching Gigabit Ethernet • IP/IPX Routing via high 100/1000 Mbps links • “One Arm” router using 802. 1 Q VLAN trunks • Layer 3 hardware routing switches with n Mbps throughout/ n usec latency ATM Routing via high speed 100/1000 Mbps Ethernet links VLAN trunks with ATM VNR proven Layer 3 switching via ATM Forum MPOA - initially IP then IPX

Supported Applications Gigabit Ethernet ATM • LAN/MAN Technology • Data only traffic - but optimised for IP …. Vo. IP, video etc. • Enough Bandwidth to support everything • Qo. S (To. S/priority) from 802. 1 P, RSVP, Diffserv etc. • Switch-to-switch 802. 3 x flow control - source quench “pause” frames • LAN / MAN / WAN • Traffic Types: Data, Voice, Video • APIs use Qo. S and optimise traffic for specific applications • Sophisticated Qo. S: UBR, CBR, VBR(rt/nrt), ABR policed traffic contract - peak, mean, burst etc. • End-to-end flow control, traffic shaping queues, CLP bit discard

Network Management Gigabit Ethernet • Simple adaptation of Ethernet MIBs • Compatibility with existing management applications ATM • ATM Forum MIBs and proprietary MIBs in current use • WAN MIBs to be finalised • ATM VC connectionless complexity introduces network management challenges

Investment/Ease of Use Gigabit Ethernet ATM • “Plain old Ethernet”? frame format - actually technical differences • Low risk / low lost feeling - 10>1000 Mbps • Not many new skills required for support low training costs • Solid proven technology - many reference installations • Anchorage Accord simplified ATM forum standards - new standards, new features • Some Administrative & Training Costs

Thank You - Questions? John A. Clark Bay Networks Technical Account Manager John. Clark@Anixter. Com