Broadband First-Mile Technologies

 

 

Tom Schmidt

Schmidt Consulting

Revised 24 November 2007

tom@tschmidt.com

http://www.tschmidt.com

 

 

 

 

 

 

 

Abstract

 

Internet popularity is driving demand for ever-faster first-mile access and exerting downward pressure on price. A few years ago residential customers were limited to low speed dialup. Today many are served by multi megabit broadband that costs only slightly more then dialup.  This paper discusses various technologies used to deliver high speed Internet access and role played by the ISP.
Table of Contents

 

1     Broadband ISP Overview... 1

1.1      Essential Functions. 1

1.1.1       First-Mile Access. 1

1.1.2       Packet Routing. 2

1.1.3       InterExchange Carrier connection. 2

1.1.4       Customer Authentication. 2

1.1.5       IP Address Allocation. 2

1.1.6       IGMP Multicast 3

1.1.7       Quality of Service (QoS). 3

1.1.8       Billing. 3

1.1.9       Customer Service. 3

1.2      Non Essential Functions. 3

1.2.1       DNS. 4

1.2.2       E- mail 4

1.2.3       UseNet 4

1.2.4       Web Hosting. 4

1.2.5       Voice over IP telephony (VoIP). 4

1.2.6       Fixed Mobile Convergence. 4

1.2.7       Virtual Private Networking (VPN). 4

1.2.8       IP Television (IPTV). 4

1.3      Service Level Agreement.. 5

1.4      Acceptable Use Policy.. 5

1.5      Blocked Ports. 5

1.6      Latency vs Speed.. 5

1.7      Asymmetric Speed.. 5

1.8      Traffic Shaping.. 6

1.9      Speed Optimization.. 6

1.10     When “Unlimited” Doesn’t Mean “Unlimited”. 6

1.11     When “Always On” Doesn’t Mean “Always On”. 6

1.12     Security and Privacy.. 6

1.13     Network Neutrality.. 7

1.14     Finding an ISP. 7

2     Plain Old Telephone Service (POTS Dialup) 8

2.1      MultiLink.. 8

2.2      Dial Up Optimization.. 8

3     T-1 and E-1 Carrier.. 10

3.1      Converting Voice to Digital Bits. 10

3.2      Channelized vs. Unchannelized.. 10

3.3      Provisioning.. 10

3.4      CSU and DSU.. 10

3.5      Smart Jack.. 10

3.6      Beyond T-1. 11

4     Integrated Service Digital Network (ISDN) 12

5     Digital Subscriber Line (xDSL) 14

5.1      Splitter vs Microfilter.. 15

5.2      Impairments. 16

5.2.1       Loop Carrier. 16

5.2.2       NID, MTU and Half Ringer. 16

5.2.3       Distance. 17

5.2.4       Bridged Taps. 17

5.2.5       Load Coils. 17

5.2.6       Noise and Crosstalk. 18

6     Data Over Cable Interface Specification (DOCSIS) 19

6.1      Impairments. 20

6.1.1       Shared Medium.. 20

6.1.2       Limited Upload. 20