Other Network Protocols

dargspurNetworking and Communications

Oct 27, 2013 (3 years and 9 months ago)

116 views

1

Computer Networks

Other Network Protocols

2

Motivation

Even though TCP/IP may have won the
protocol wars, you will be able to
understand networking and even TCP/IP
better if you learn about contrasting
solutions and implementations. This may
help you to avoid reinventing the wheel or
perhaps to borrow from the past's good
ideas to solve seemingly new problems.

3

Novell IPX/SPX

Novell proprietary

Based on Xerox's XNS protocol system

Runs on top of Ethernet, Token Ring, etc.

Usually used with NetWare OS's

Very popular in corporate environments

Declining usage

4

Novell Protocol Stack Illustrated

5

Internetwork Packet eXchange
(IPX)

32
-
bit network, 48
-
bit node/host address

Network is generally fixed at 32
-
bits

Node address = IEEE 802 MAC address

Dynamic host address assigment

Many features IP wishes it had!

6

IPX Routing

IPX Routing Information Protocol

TTL counts up

NLSP

Similar to OSPF and IS
-
IS

Never took off

Concept of internal IPX numbers

7

Sequenced Packet eXchange
(SPX)

Similar to TCP, but with no sliding window!

SPX II addressed the window size problem

Though, not really well

Most Novell based apps avoided SPX

It was inefficient and just got in the way

Some newer apps used SPX II (e.g. Notes)

8

Service Advertisement Protocol
(SAP)

Services are advertised periodically

The anti
-
DNS system

e.g. "I'm a Netware printer, here I am!"

Default interval was every 60 seconds

Very chatty on large networks

Does not scale

NDS was supposed to help

9

NetWare Core Protocol (NCP)

Novell's layer 5, 6 and 7 layers
-

kinda

File access protocol

Print services

Login/authentication requests

Messaging/management services

Provided "burst mode" for file read/writes

10

NetWare Directory Services
(NDS)

Hierarchical database of network objects

Based on X.500 and works with LDAP

Logical and physical objects represented

Leafs, containers, users, drive mapping, etc.

Naming structure similar to DNS

e.g. jdoe.networks.acme_us.

Partitions and replicas stored on servers

11

AppleTalk

De Facto standard from Apple for Macs

Very easy for end users

Very chatty
-

scaling problems

Runs on top of LocalTalk, Ethernet, Token
Ring, etc.

TokenTalk and EtherTalk technologies
developed to support AppleTalk over IEEE
LANs

12

This Picture is Wrong!

13

AppleTalk Network Layer
Addressing

Only 3 bytes for network layer addresses!

2 bytes for network, 1 byte for host/node

Networks can be
ranges

e.g. 135
-
141

Arbitrary size, unlike IP (x
2
)

Looks/Requests network address

Chooses host/node address at random!

Sends an AARP and looks for a reply

14

AppleTalk Routing

Routing Table Maintenance Protocol (RTMP)

Similar to RIP

Seed Router

1 router configured with network, others learn

Nodes can optimize best exit router by
examining received packets

Associates NET with ROUTER ADDRESS

15

AppleShare

Centralized file sharing system

Runs on top of AppleTalk

Also allows for

Printer sharing

Peer to peer sharing

Mail handling

Security functions (ids and passwords)

16

ISO Network Layer

Connectionless Network Layer Protocol
(CNLP)

Variable length, 20 bytes max

Address specifies a host rather than an
interface

Was considered to replace IPv4

Provided for autoconfiguration like IPv6 and
IPX

17

ISO Routing

Intermediate System to Intermediate System
(IS
-
IS)

Link state routing protocol

Very similar to OSPF

Widely used by many ISPs

Runs directly on top of a layer 2 protocol

18

ISO Transport Layer

Transport Protocol (TP)

Four classes of transport layer protocols

TP0, TP1, TP2, TP3, TP4

Each provide increasing degree of features

TP4 is similar to TCP

Three
-
way handshake

Sliding window

Retransmission timer

19

ISO Protocol Stack Illustrated

20

DECnet

Most commonly referred to as Phase IV

Earlier phases and Phase V also defined

DECnet Phase V was CLNP or IP

Only 2 bytes for addresses in Phase IV!

6 bits for network (area), 10 bits for host/node

Traditionally implemented on Digital
Equipment Corp. machines (e.g. VAX)

Ported to many other systems

21

DECnet Protocol Stack Illustrated

22

Systems Network Architecture
(SNA)

Proprietary architecture from IBM

There is no true layer 3 function in legacy
SNA
-

no routing!

Historically built for token ring and source
routing (that was the layer 3 network)

Central control (dumb terminals)

APPN came later to provide distributed
control

23

SNA Protocol Stack Illustrated

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SNA Components

Hosts (mainframe)

Communications controller/FEP

Cluster controllers
-

like a hub

Terminals and printers

Software (VTAM, NCP, emulation)

Physical and logical concepts (PUs/LUs)

25

Network Basic Input Output
System (NetBIOS)

A simple API for LAN applications

Assigns names for nodes on the network

Very chatty
-

does not scale

No network layer

Often uses the NetBIOS Extended User
Interface (NetBEUI)

Server Message Block (SMB) used to provide
file/print sharing (e.g. Samba)