Routers and Router Markets
Mika Hatanpää
1998
Overview of routing and routers
Router classification
Router vendors
Router markets
Router products
Some parts of this material is are for Nokia internal use only!!!
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
page: 1
Levels of analysis in this presentation
Products
Markets
• Some examples and test results
• Vendors and market situation
Specifications, RFCs, draft specs
• Routers according to RFC's
Protocols
Principles, Requirements
© NOKIA
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Layers of the TCP/IP stack
- Hosts and routers The coloured areas of the
router box are the most interesting
ones in this presentation
Host 1
Router
Application
Routing
Application
TCP/
UDP
TCP/
UDP
TCP/
UDP
IP
IP
Data Link
Data Link
Network 1
© NOKIA
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Host 2
IP
Data Link
Network 2
Routing and routers (1/5)
•
Routing is a process that routes traffic from source to destination according to
addresses, quality requirements, and constraints set by the network
•
Routers are devices that perform the network layer (layer 3) forwarding function
of the Internet protocol suite.
•
•
The Internet community usually refers to such devices as IP routers or simply routers.
An IP router can be distinguished from other sorts of packet switching devices
in that a router examines the IP protocol header as part of the switching
process.
© NOKIA
•
It generally removes the Link Layer header a message was received with, modifies
the IP header, and replaces the Link Layer header for retransmission.
•
There exists also devices that do packet switching on the link layer (layer 2) but these
devices are usually called bridges or switches.
•
However, the differences between routers and switches are becoming more and
more fuzzy
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Routing and routers (2/5)
•
Historically, routers have been realized with packet-switching software executing
on a general-purpose CPU.
•
•
A router connects to two or more logical interfaces, represented by IP subnets or
unnumbered point to point lines.
•
•
•
As custom hardware development becomes cheaper (ASICs) and as higher throughput
is required, special purpose hardware is becoming increasingly common!
it has at least one physical interface (usually at least 2)
Forwarding requires the router to choose the address and relevant interface of the
next-hop router or (for the final hop) the destination host.
•
•
Forwarding depends upon a route database (routing table) within the router.
•
A router accomplishes this by participating in distributed routing and reachability
algorithms with other routers (routing protocols)
The routing database should be maintained dynamically to reflect the current topology of
the Internet system
Routers provide datagram transport only, and they seek to minimize the state
information necessary in the interest of routing flexibility and robustness.
© NOKIA
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Routing and routers (3/5)
A characteristic router performs the following functions:
1. Conforms to specific Internet protocols including the Internet Protocol (IP),
Internet Control Message Protocol (ICMP), and others as necessary (routing
protocols)
2. Interfaces to two or more packet networks. For each connected network the
router must implement the functions required by that network. These functions
typically include:
© NOKIA
•
encapsulating and decapsulating the IP datagrams with the connected network
framing (e.g., an Ethernet header and checksum)
•
sending and receiving IP datagrams up to the maximum size supported by that
network, this size is the network's Maximum Transmission Unit or MTU
•
translating the IP destination address into an appropriate network-level address for
the connected network (e.g., an Ethernet hardware address), if needed
•
responding to network flow control and error indications, if any.
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Routing and routers (4/5)
3. Receives and forwards Internet datagrams. Important issues in this process
are buffer management, congestion control, and fairness
•
Recognizes error conditions and generates ICMP error and information messages
as required.
•
•
Drops datagrams whose time-to-live fields have reached zero.
Fragments datagrams when necessary to fit into the MTU of the next network.
4. Chooses a next-hop destination for each IP datagram, based on the
information in it's routing database.
5. Supports an interior gateway protocol (IGP) to carry out distributed routing
and reachability algorithms with the other routers in the same autonomous
system.
•
In addition, some routers will need to support an exterior gateway protocol (EGP) to
exchange topological information with other autonomous systems.
6. Provides network management and system support facilities, including
loading, debugging, status reporting, exception reporting and control.
© NOKIA
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Routing and routers (5/5)
•
General requirements for routers:
•
Advanced Routing and Forwarding Algorithms
•
•
High Availability
•
•
•
always working, instant recovery, robusticity, …
Advanced O&M Features
•
normal operation should not require O&M, remote operation
•
monitoring, diagnostics, statistics, …
High Performance
•
© NOKIA
highly dynamic, minimal overhead, …
the lines are currently full...
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Router requirements (1/10)
- Link layer requirements •
Routers have essentially the same Link Layer protocol requirements asother
sorts of Internet systems
•
The information that must pass from the Link Layer to the Internetwork Layer
for each received packet is:
© NOKIA
•
•
The IP packet
•
•
The identity of the physical interface from which the IP packet was received
•
Also the source physical address should be provided
The length of the data portion (i.e., not including the Link-Layer framing) of the Link
Layer frame
The classification of the packet's destination physical address as a Link Layer
unicast, broadcast, or multicast
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Router requirements (2/10)
- Link layer requirements •
The information that must pass from the Internetwork Layer to the Link Layer
for each transmitted packet is:
•
•
•
•
•
The IP packet
The length of the IP packet
The destination physical interface
The next hop IP address
Also the Link Layer priority value should be provided
•
The Link Layer must notify the Internetwork Layer if the packet to be
transmitted causes a Link Layer precedence-related error
•
Routers that have point to point general purpose serial interfaces must
implement PPP
© NOKIA
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Router requirements (3/10)
- Internet layer protocols •
Routers must implement IP and ICMP protocols
•
•
•
•
IGMP should be implemented as well
A router must support fragmentation and reassembly
A router must implement mandatory IP extensions:
•
•
•
© NOKIA
There are many optional features however
subnets
IP broadcast
Classless Inter-Domain Routing (CIDR)
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Router requirements (4/10)
- Forwarding algorithm 1. The router receives the IP packet from the Link Layer.
2. The router validates the IP header.
•
Note that IP reassembly is not done, except on IP fragments to be queued for local
delivery in step (4)
3. The router performs most of the processing of any IP options.
•
some IP options require additional processing after the routing decision has been made.
4. The router examines the destination IP address to determine how it should
continue to process the IP datagram. There are three possibilities:
•
•
The IP datagram is destined for the router, and should be queued for local delivery, doing
reassembly if needed
•
•
The IP datagram is not destined for the router, and should be queued for forwarding
The IP datagram should be queued for forwarding, but (a copy) must also be queued for
local delivery
The next steps are diferent for unicast and multicast!
© NOKIA
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Router requirements (5/10)
- Forwarding algorithm for unicast 5. The forwarder determines the next hop IP address for the packet, usually by
looking up the packet's destination in the router's routing table.
•
This procedure also decides which network interface should be used to send the
packet.
6. The forwarder verifies that forwarding the packet is permitted.
•
•
The source and destination addresses should be valid
If the router supports administrative constraints (like firewalls) on forwarding, those
constraints must be satisfied.
7. The forwarder decrements (by at least one) and checks the packet's TTL
8. The forwarder performs any IP option processing that could not be completed
in step 3.
9. The forwarder performs any necessary IP fragmentation
•
© NOKIA
Since this step occurs after outbound interface selection (step 5), all fragments of
the same datagram will be transmitted out the same interface.
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Router requirements (6/10)
- Forwarding algorithm for unicast 10. The forwarder determines the Link Layer address of the packet's next hop.
•
The mechanisms for doing this are Link Layer-dependent
11. The forwarder encapsulates the IP datagram for the link layer
•
•
an appropriate Link Layer frame is used
The link layer frames are queued for output on the interface selected in step 5.
12. The forwarder sends an ICMP redirect if necessary
•
•
The ICMp redirect tells a local host to use different next hop router
The forwarding algorithm is slightly different for multicast and there exists an
extensive amount of other rules for the forwarding process...
© NOKIA
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Router requirements (7/10)
- Transport layer •
•
© NOKIA
A router is not required to implement the transport layer protocols
But the application protocols (like routing protocols) usually require
both TCP and UDP to be present
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Router requirements (8/10)
- Application layer, Routing protocols •
The most important application layer protocols are the routing protocols for
Interior and Exterior routing
•
Requirements for interior routing protocols (IGP) are:
•
•
Respond quickly to changes in the internal topology of an AS
•
•
•
•
Provide quick convergence to loop-free routing
Provide a mechanism such that circuit flapping does not cause continuous routing
updates
Utilize minimal bandwidth
Provide equal cost routes to enable load-splitting
Provide a means for authentication of routing updates
•
A router that implements any routing protocol other than static routing must
implement OSPF !!!
•
A router that implements any exterior routing protocol must implement BGP !!!
© NOKIA
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Router requirements (9/10)
- Application layer, Management protocols •
Routers must be manageable by SNMP
•
•
•
•
Standard MIBs for routing protocols must be used
Vendor specific MIBs can be used
No other MUST requirements
BOOTP could be used for bootloading and configuting...
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
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Router requirements (10/10)
- O&M •
Router O&M includes the following kinds of activities:
© NOKIA
•
Diagnosing hardware problems in the router's processor, in its network interfaces,
or in its connected networks, modems, or communication lines.
•
•
•
•
Installing new hardware
•
Detecting and diagnosing Internet problems such as congestion, routing loops, bad
IP addresses, black holes, packet avalanches, and misbehaved hosts.
•
Changing network topology, either temporarily (e.g., to bypass a communication
line problem) or permanently.
•
•
•
Monitoring the status and performance of the routers and the connected networks.
Installing new software
Restarting or rebooting the router after a crash
Configuring or reconfiguring the router (a router must provide out-of-band access in
addition to the in-band access)
Collecting traffic statistics for use in (Inter-)network planning.
Coordinating the above activities with appropriate vendors and telecommunications
specialists.
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Router classification (1/2)
•
Personal routers (PR)
•
•
•
•
•
typically from 1 to 10 IP addresses
WAN interfaces: asynchronous, serial, and integrated services digital network (ISDN)
list prices are from U.S.$500 to U.S.$1,500
Branch office routers (BOR)
•
•
•
•
routers targeted for individual users or very small offices
routers used to link remote LANs to a corporate network (not access servers)
serial, leased-line interfaces or frame relay interfaces and may have dial backup
they are multiprotocol
Midrange routers (MRR)
•
•
routers typically configured with up to 24 LAN and 24 WAN ports
•
Examples: Cisco Systems Inc.'s 4000 series, 3Com Corporation's NETBuilder II, and Bay
Networks Inc.'s LN family.
© NOKIA
incorporate multiple media, such as Ethernet and token ring, Fast Ethernet, FDDI, and
ATM.
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Router classification (2/2)
•
High-end routers (HER)
•
•
•
•
•
routers typically configured with a minimum of 24 LAN and 24 WAN ports
incorporate multiple media, such as Ethernet, Fast Ethernet, token ring, FDDI, and ATM
fault tolerance suported: dual power supplies, hot swappable cards, redundant buses, …
Examples: Cisco's 7500 and Bay's BN family
Multigigabit routers (MGBR)
•
routers capable of providing multigigabit bandwidth in support of high-speed WAN
interfaces.
•
•
typically designed for the Internet Core and support only the IP protocol suite
•
fault tolerance supported: dual power supplies, hot swappable cards, and redundant
buses.
•
Examples: Cisco's 12000 (GSR) and Ascend's GRF family
© NOKIA
media types include ATM (OC-3, OC,-12, and OC-48), IP over SONET, high-speed serial
interface (HSSI), and in the future wave-division multiplexing (WDM)
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Typical IP network architecture
ADSL
PSTN/ISDN, (PR)
PC
File Edit LocateView
Topology
Network
Traffic
Help
Help
Mount
431
7437
1950
79%
/
GSM
PC
File Edit LocateView
Topology
Network
Traffic
HUB/SWITCH
Help
Help
Mount
431
7437
1950
79%
/
ACCESS ROUTER
PC
File Edit LocateView
Topology
Network
Traffic
Help
Help
Mount
431
7437
1950
79%
/
SWITCH/ROUTER
PC
File Edit LocateView
Topology
Network
Traffic
Help
Help
Mount
431
7437
1950
79%
/
(BOR,MRR)
ACCESS SERVER
PC
File Edit LocateView
Topology
Network
Traffic
HUB/SWITCH
Help
Help
Mount
431
7437
1950
79%
/
EDGE ROUTER
(MRR, HER, MGBR)
PC
File Edit LocateView
Topology
Network
Traffic
© NOKIA
Help
Help
Mount
431
7437
1950
79%
/
IPROUT98.ppt / 04.10.1998 / Mha
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Internet
(HER, MGBR)
Router vendors - Cisco (1/2)
•
•
Cisco Systems is the worldwide leader in networking for the Internet
Cisco has three lines of business:
•
Enterprises - Large organization with complex networking needs. Enterprise customers
include corporations, government agencies, utilities and educational institutions.
•
Service Providers (ISPs) - Companies that provide information services, including
telecommunication carriers, Internet Service Providers, cable companies, and wireless
communication providers.
Small/Medium Business – Companies with a need for data networks of their own, as well
as connection to the Internet and/or to business partners.
•
•
•
•
•
Cisco sells its products in approximately 115 countries
Cisco has grown very fast by doing acquisitions
Cisco has formed alliances with Telcos
Cisco sells
•
•
•
© NOKIA
Routers (like 7000 and 12000 series)
LAN Switches (Catalyst products)
ATM Switches, WAN Switches, Firewalls, …
IPROUT98.ppt / 04.10.1998 / Mha
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Router vendors - Cisco (2/2)
•
Financial facts:
•
1995
1994
1993
Net sales
$6,440
$4,096
$2,232
$1,334
$714
Net income
$1,048
$913
$456
$332
$176
Net income per share
1,52
1,37
0,72
0,54
0,30
Total assets
$5,451
$3,630
$1,991
$1,129
$656
about 8,000 in the San Francisco Bay Area
Cisco's market shares in some key areas (1Q98):
•
•
•
•
•
© NOKIA
1996
Cisco employs approximately 15,600 worldwide
•
•
1997
Routers: 63%
LAN Switches: 45%
ATM WAN Switches: 31%
ATM LAN Switches: 21%
Remote access: 26%
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Router vendors - Bay Networks
•
•
•
•
•
•
Bay Networks is one of the big datacom companies
Bay Networks has more than 7,000 employees operating in 90 countries
Key figures:
1996
1995
Net sales
$2,093
$2,057
$1,404
Net income (loss) per share
$(1.46)
$1.04
$0.69
Bay networks is currently a Nortel Networks Business!
Like Cisco Bay has also done many strategic acquisitions
Bay networks sells:
•
•
•
•
•
•
•
1997
Remote access concentrators and servers
Backbone routers (Accelar gigabit router)
Cable modems, Access Nodes (BayStack)
ATM Switches (Centillion)
LAN Switches, HUBs
Bay has about < 20% market share in LAN Switches and ATM LAN Switches
New products like cable modems and Accelar Switches seem quite promising...
© NOKIA
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Router Vendors - Ascend
•
•
Ascend has grown very fast by making strategic acquisitions
Financial facts:
•
•
•
© NOKIA
1997
1996
1995
1994
1993
Net Sales
$1,167
$890
$287
$89
$23
Net income (loss)
($124)
$183
$52
$15
($2)
Net income (loss) per share
($1)
$1
$0
$0
($0)
Total Assets
$1,137
$922
$481
$126
$31
Ascend Communications, Inc. was founded in 1989
Ascend products are
•
•
Edge layer products like xDSL modems
•
•
Core layer products like the new GRF gigabit router and ATM WAN Switches
Access layer products like access concentrators (Ascend has quite big market
share here)
Ascend has not got LAN products
Ascend has about 1700 employees
IPROUT98.ppt / 04.10.1998 / Mha
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Router vendors - 3Com
•
3Com is one of the biggest datacom companies but routers do not play a key
role in it's product portfolio
•
Financial facts:
•
1996
1995
Net Sales
$3,147
$2,327
$1,593
Net income
$373
$177
$144
Total assets
$2,266
$1,525
N/A
3Com's product mix includes for example:
•
•
•
•
•
•
•
1997
Network interface cards
High-speed modems (analog, ISDN, cable and DSL)
Hubs, Switches
Routers
Internet access devices, Remote access equipment
3Com has approximately 13,000 employees worldwide
3Com acquired US Robotics last year
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
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Router vendors - Nokia
•
•
Nokia is not a big router vendor
The only true Nokia Routers are the ones developed by IPRG
•
•
IP400 Series
Nokia's financial figures for comparision (1 USD = 5 FIM in calculations):
© NOKIA
1997
1996
Net sales
$10,522
$7,864
Operating profit
$1,691
$853
Net profit
$1,252
$653
Earnings per share
$4,23
$2,35
IPROUT98.ppt / 04.10.1998 / Mha
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For internal use only !
Router markets (1/4)
The contents of this slide are for Nokia employees only.
If you are such a person ask for another copy of this slide
set from mika.hatanpaa@ntc.nokia.com
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
page: 28
For internal use only !
Router markets (2/4)
The contents of this slide are for Nokia employees only.
If you are such a person ask for another copy of this slide
set from mika.hatanpaa@ntc.nokia.com
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
page: 29
For internal use only !
Router markets (3/4)
The contents of this slide are for Nokia employees only.
If you are such a person ask for another copy of this slide
set from mika.hatanpaa@ntc.nokia.com
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
page: 30
For internal use only !
Router markets (4/4)
The contents of this slide are for Nokia employees only.
If you are such a person ask for another copy of this slide
set from mika.hatanpaa@ntc.nokia.com
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
page: 31
Router products - Cisco 7513 (1/3)
•
Supported network interfaces:
•
•
•
•
•
•
•
•
•
•
•
•
•
Ethernet 10BaseT, AUI1, and 10BaseFL
Fast Ethernet (100BaseT and MII)
Token Ring
FDDI (half and full duplex)
HSSI
Synchronous serial
ATM
Multichannel on T1 or E1 lines, ISDN PRI
Channelized T3
Packet OC-3
IBM channel
Power supplies: 2
Interface processor slots: 11
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
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Router products - Cisco 7513 (2/3)
•
Route Switch Processor module (2 slots)
•
•
•
•
•
•
•
•
Processor type: MIPS RISC 100-200 MHz
32-MB DRAM default, upgradeable to 128 MB
16-MB Flash memory via PCMCIA Flash memory cards, upgradeable to 40 MB
Battery backup
Real-time calendar clock
Dimensions (H x W x D): 85.73 x 44.45 x 55.88 cm
Weight: Chassis with blower module, 2 power supplies and all slots filled: 72.58 kg
Software options:
© NOKIA
•
•
IP Routing Protocols: RIP, OSPF, BGP-4, IGRP, ….
•
IP Router Functionality: IP, UDP, TCP, ICMP, ARP, CIDR, BOOTP, DHCP, TFTP, PPP,
SLIP, Telnet, Finger, RARP, TACACS, SNMP, …
•
Link layer support for all possible interface types …
IP Multicast Protocols: DVMRP, IGMP, ...
IPROUT98.ppt / 04.10.1998 / Mha
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Router products - Cisco 7513 (2/3)
•
Capacity is highly dependent of the media type used and the configuration of
the router
•
© NOKIA
Cisco 7513 equiped with 200MHz MIPS RISC CPU, VIP Distributed Optimum
Switching modules, and Full Duplex Fast Ethernet Cards routes over 1M packets
per second when using 64 byte IP packets.
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Router products - Nokia IP400 (1/4)
•
Nokia Software Specifications of IP400
•
IP Routing Protocols: RIP, OSPF, IGRP, BGP-4,
Route redistribution,
•
•
IP Multicast Protocols: DVMRP, IGMP
•
Redundancy: Virtual Router Redundancy
Protocol
•
•
Checkpoint Firewall
© NOKIA
IP Router Functionality: IP, ICMP, ARP, Router
discovery, CIDR, BOOTP, DHCP, Relay agent, ...
Interfaces supported by SW:
•
Ethernet/Fast Ethernet
•
Fiber Distributed Data Interface (FDDI)
•
Asynchronous Transfer Mode (ATM)
•
Frame Relay (available early 1998)
•
Point-to-Point Protocol
•
Cisco HDLC
IPROUT98.ppt / 04.10.1998 / Mha
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Router products - Nokia IP400 (2/4)
•
•
Network Management
•
Command line via Telnet
•
Software and Configuration via File Transfer Protocol (FTP)
•
Simple Network Management Protocol (SNMP), basic MIBs
•
Voyager Web tool via HyperText Transfer Protocol (HTTP)
Nokia Hardware Specifications IP440
•
•
PentiumPro processor
Interfaces
•
•
© NOKIA
ATM
155 Mbps SONET/SDH STS3c/STM1
Unshielded Twisted Pair
155 Mbps SONET/SDH STS3c/STM1
Multimode Fiber
Ethernet/Fast Ethernet
IEEE 802.3 10BASE-T, 100BASE-TX
Unshielded Twisted Pair
Half- or Full-Duplex
IPROUT98.ppt / 04.10.1998 / Mha
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RJ45 Connector
SC Connector
RJ45 Connector
Router products - Nokia IP400 (3/4)
•
… Interfaces
•
•
•
© NOKIA
FDDI
ISO9314/ANSI X3T9.5
Multimode Fiber
Dual Attachment Station
Synchronous Serial
T1/E1 synchronous serial
Clocking to 2.048 Mbps
SC Connectors
ITU-T V.35, X.21
Physical size
•
19-inch Rack Mountable
•
Dimensions: HxDxW
18 x 46 x 43 cm
•
Weight
42 lbs (19 kg)
without interfaces
IPROUT98.ppt / 04.10.1998 / Mha
page: 37
For internal use only !
Ipsilon routing kernel SW architecture (4/4)
- Outdated information -
The contents of this slide are for Nokia employees only.
If you are such a person ask for another copy of this slide
set from mika.hatanpaa@ntc.nokia.com
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
page: 38
Routing protocols etc. (1/2)
•
Routing Information Protocol (RIP, RFC 1058)
•
•
Open Shortest Path First (OSPF, RFC 1247)
•
•
Not an IETF standard, but commonly used with equipment from Cisco Systems,
IGRP's fine-grained metrics make it particularly useful in networks with mixedspeed links, such as those supporting both FDDI and Ethernet in parallel.
Border Gateway Protocol (BGP, RFC 1654)
•
•
A more advanced IP routing protocol, OSPF uses a link-state algorithm for faster
convergence around failures. Support for variable-length subnet masks (CIDR)
makes it particularly useful in networks where IP addresses must be conserved.
Interior Gateway Routing Protocol (IGRP)
•
•
The simplest IP routing protocol, RIP is ideal for straightforward network topologies.
Workstations also use RIP to send their traffic along an optimal, reliable path.
BGP is a highly sophisticated IP routing protocol mostly used by ISPs. Support for
detailed policy controls make it particularly useful between administrative domains.
Static Routing
•
© NOKIA
Support for static routes allows the network designer to use manual intervention to
override routing protocols.
IPROUT98.ppt / 04.10.1998 / Mha
page: 39
Routing protocols etc. (2/2)
•
Redistributed Routing
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Scalable IP Multicast
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The purpose of IP multicast protocols is to deliver a stream of IP packets to multiple
destinations quickly and efficiently.
Distance Vector Multicast Routing Protocol (DVMRP, RFC 1075)
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Support for redistributed routes allows the network designer to propagate routes
learned from one protocol into other protocols. For example, backbone routes
learned via OSPF can be redistributed to workstations via RIP. As another example,
routes learned from Cisco equipment via IGRP can be redistributed to standardsbased equipment via OSPF. Filters allow network designers to propagate route
information selectively, enhancing network security.
This specialized IP routing protocol complements the unicast protocols described
above to create a logical tree along the most efficient path between the source and
all destinations. DVMRP is widely used in the MBONE, a large-scale multicast
overlay across the Internet.
Internet Group Membership Protocol (IGMP, RFC 1112)
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© NOKIA
Used with DVMRP, this protocol allows applications and hosts to indicate which IP
multicast packets they wish to receive.
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The relative advantages of bridging and routing
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Advantages of Bridging
Advantages of Routing
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Provides simpler installation and
configuration
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Provides simpler administration of network
security
Automatically locates users via 'self-learning'
capabilities
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Helps comply with TCP/IP address
restrictions if using the Internet Network
Handles all protocols
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Uses WAN links more efficiently because
they do not carry LAN framing overhead
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Isolates broadcast traffic to individual LANs
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http://www.ktgroup.co.uk/techinfo/abtbridge
s.html
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Provides more flexibility
Protects investment as needs change
Does not require software upgrades for new
releases of each protocol
Uses automatic path optimisation
May reduce total overhead
Useful for lower-speed WAN links
Complements bridging in large networks
IEEE 802.1 standard spanning Tree Protocol
One path control algorithm for all protocols
Provides automatic re-routing
Results in lower cost of ownership
Fewer staff needed
Fewer software upgrades required
© NOKIA
IPROUT98.ppt / 04.10.1998 / Mha
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