Transcript Ethernet Tree Service - IT246

Prof. Alfred J Bird, Ph.D., NBCT
http://www.cs.umb.edu/~abird
[email protected]
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LAN –Local Area Network
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In most cases now, these are Ethernet Networks
Interconnect sites that are close to each other, for
example in the same building.
WAN – Wide Area Network
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Generally use the TELCO network for
communications
Interconnect sites that are geographically distributed
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DS-0
T1 (DS-1)
T2 (DS-2)
T3 (DS-3)
T4 (DS-4)
64kbps (56kbps)
1.544Mbsp
6.312Mbps
44.763Mbps
274.176Mbps
E1
E3
2.048Mbps
34.368Mbps
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Multiplexed – Combining data packets for
transport
Point of Presence (POP) – The point where the
customer connects the network data traffic to
the communications carrier
Line of Demarcation – The point where
ownership of the communications equipment
changes from the communications carrier to the
user
CSU/DSU – The Channel Service Unit / Data
Service Unit
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Red Alarm – A local equipment alarm that
indicates that the incoming signal has been
corruptes
Yellow Alarm – Indicates that a failure in the
link has been detected
Blue Alarm – Indicates a total loss of incoming
signal
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HDLC – High Level Data Link Control
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PPP – Point to Point Protocol
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High level data link control, a synchronous
proprietary protocol
Generally used with modems
Data Encapsulation – The data is properly
packages for transport over a serial
communications line
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V.44/V.34 – The standard for all analog
modem connections with a maximum data rate
of 34 kbps
V.92/V.90 – The standard for a combination of
analog and digital modem connections with a
maximum data rate of 56kbps
Asymmetric Operation – Describes the modem
operation where the data transfer rate to and
from the service provider differs
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Capitalize on the high-bandwidth network of a
cable provider two-way to deliver high speed
data
Data rates can range up to (and maybe greater
than) 50Mbps
Potential of collisions problems
Currently using ethernet protocols
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Fiber Optical Network
Not available everywhere
Performance equal to cable modem systems
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DSL – Digital Subscriber Line
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DSL uses a point to point technology
Sends signals over copper telephone lines
Limited ranges
xDSL – generic term for many forms of DSL
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ADSL – Asymmetric DSL - <18,000ft
SDSL – Symmetric DSL - < 10,000ft
Many other (see the text)
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RAS - Remote Access Server
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The last piece needed to gain access to the network
Provided by the POTS (Plain Old Telephone Service)
or the cable modem or other types of connections
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Why not use Ethernet protocols for a WAN?
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Ethernet now has speeds up to 10Gbps
IT has been doing a lot of engineering and development
work on Ethernet equipment and protocols.
Three (3) types of technologies defined by the MEF
(Metro Ethernet Forum)
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Ethernet Line Service (E-Line)
 Point to point service
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Ethernet ELAN Service (E-LAN)
 Multipoint to multipoint service
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Ethernet Tree Service (E-Tree)
 Point to multipoint service
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Point to point connection
Similar to a dedicated leased line, frame relay
or ATM
From the customer it appears everyone is on
the same LAN
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Provides connectivity to two or more
subscribers
It appears to the customer that everyone on on
the same LAN
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Like a hub and spoke service. Called a root and
leaf environment
Customer sites cannot exchange traffic with
each other
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CIR - (Committed Information Rate)
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CBR – (Committed Burst Size)
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The traffic size that is allowed to burst
EIR – (Excess Information Rate)
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Bandwidth the network must deliver
Average size in bps used to allow traffic greater that
the CIR when the network is not busy
EBS – (Excess Burst Size)
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Burstable size allowed when the when the traffic is
in the EIR mode
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DHCP – Dynamic Host Configuration Protocol
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Extension of BOOTP (Bootstrap Protocol)
Way to assign IP addresses to a networked computer
DNS – Domain Name Service
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Way to match up a URL to an IP
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The networked computer issues a request
using a broadcast to find a DHCP server
The DHCP server sends an IP to the networked
computer
Will also send other info such as lease time,
gateway, subnet mask, etc.
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Forward Domain Name Service
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Translation of a URL (name) to a IP address
Reverse Domain Name Service
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Translation of an IP address to an URL (name)
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IANA – Internet Assigned Name Authority
ICANN – Internet Corporation of Assigned
Names and Numbers
Domain Registers
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A organization that is authorized to register Internet
domain names