Transcript Overview - NobbyVille

Gigabit Ethernet
Vs
Asynchronous Transfer Mode
John A.Clark
Bay Networks Technical Account Manager
[email protected]
Not a Desktop Debate
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1995
1996
Ethernet
1997
Fast Ethernet
1998
Token Ring
1999
ATM
2000
• 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
1998E
SNA
IPX
Source: Gartner Group 3/97
2000E
Others
2002E
NetBEUI
• IP has emerged as the protocol of choice most organisations have a migration plan
• Few networks are IP only - other protocols
e.g. IPX, NetBEUI, SNA are still important
on existing LANs
It’s a Backbone Issue
What Technology/Business
Factors Should be Considered?
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•
•
•
•
•
•
Network Speed/distance
Standards Status
Network Resilience
Routing/Layer 3 switching
Supported Applications
Network Management
Investment/Ease of Use
Network Speed/Distance
Gigabit Ethernet
• 1000BaseCX: 25m copper
• 1000BaseSX: 550m on 50
micron MM fibre, 220m on
62.5 micron (DMD)
• 1000BaseLX: 550m all MM
fibre , 3km SM fibre - Long
reach 50km proprietary
• 1 Gbps limit - 10 Gbps ?
• 200m network diameter
restrictions - CSMA/CD as
shared media
ATM
•
•
•
•
•
25Mbps Cat V UTP
155Mbps - OC/3 fibre
622Mbps - OC/12 fibre
800+m on MM, 15km on SM
2.4Gbps - 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
•
•
•
•
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802.3z
OK
802.3ab 1000baseT tba
802.3x flow control
802.1P priority
OK
802.1Q VLAN tag OK
RSVP, RTP…Diffserv tba
ATM
• Anchorage Accord
combined standard
• IISP
• PNNI
• LANE 2.0
• MPOA 1.0
• NHRP
OK
OK
OK
OK
Network Resilience
Gigabit Ethernet
• 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
ATM
• 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
802.1Q 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
• LAN/MAN Technology
• Data only traffic - but
optimised for IP ….VoIP,
video etc.
• Enough Bandwidth to support
everything
• QoS (ToS/priority) from
802.1P, RSVP, Diffserv etc.
• Switch-to-switch 802.3x
flow control - source quench
“pause” frames
ATM
• LAN / MAN / WAN
• Traffic Types: Data, Voice,
Video
• APIs use QoS and optimise
traffic for specific
applications
• Sophisticated QoS: 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>100>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
[email protected]