Chapter 10

Fiber to the Home Commonly Provides

10 - 100 Mbps downstream 1 - 10 Mbps upstream Most common is 15 and 4

Fiber to the Home

A dedicated point-to-point fiber optic service As of 2011, 7 million US homes subscribed An optical unit network (OUN) at the customer site acts as an Ethernet switch and a router

Cable Modems

A digital service offered by cable television companies Uses hybrid fiber coax

1996 - Next Generation Internet (NGI) funded by NSF

A group called University Corporation for Advanced Internet Development (UCAID) started with 34 universities and developed the Abilene network (also called Internet 2)

Point of Presence (POP)

A place at which ISP provides service to its customers

Digital Subscriber Line (DSL)

A point-to-point technology Designed to provide high speed data transmission over traditional telephone lines Requires changing telephone equipment; not rewiring the local loop Not available in all US locations (more widespread in Asia, Europe, Canada)

Sprint's Internet Backbone

A tier 1 ISP in North America Circuits: mostly ATM OC-12; a few OC-48, and OC-192

Features of Future Internet:

Access via Gigapops, similar to NAPs: Operate at very high speeds (10 Gbps) using SONET, ATM and IPv6 protocols; Eventual plans for 1Tbps IPv6 not IPv4 New protocol development focuses on issues like Quality of Service and Multicasting New applications include Tele-immersion and Videoconferencing

Types of Digital Subscriber Line (DSL)

Asymmetric DSL (ADSL)

Types of Equipment used in Cable Modem Architecture

Cable Modem Termination System (CMTS) Fiber Node with an Optical Electrical (OE) converter Combiner (for downstream traffic only)

Combiner (for downstream traffic only)

Combines Internet traffic with TV video traffic

Implications for Mangement

Concern about traffic slowing down Internet: New fiber based circuits deployment along with Next Generation Internet Many new broadband technologies for high speed Internet access: Simple to move large amount of data into most homes and business richer multimedia apps Which access technology to dominate?

Internet Engineering Task Force (IETF)

Concerned with evolution of Internet architecture and smooth operation of Internet Work through groups (organized by topics) Request For Comments (RFC): basis of Internet standards

Network Access Points (NAPs)

Connect tier 1 ISPs together - Sometimes large tier 2 and 3 ISPs also have direct access About a dozen in the U.S. - Run by common carriers (Sprint, AT&T)

Metropolitan Area Exchanges (MAEs)

Connect tier 2 ISPs together

Tier 2 Internet Service Providers (ISPs)

Connect with tier 1 ISPs Provide services to their customers and sell access to local ISPs

Tier 3 Internet Service Providers (ISPs)

Connected to tier 1 or 2 ISPs Sell Access to individuals

Digital Subscriber Line (DSL) equipment:

Customer premises equipment (CPE) installed at customer location - contains the line splitter Local loops connect to the MDF: the MDP splits neighborhood voice and data traffic to phone network and DSLAM (DSL access multiplexer)

Size of digital channels for Asymmetric DSL (ADSL):

Depends on the distance (CPE-Office) (up to 18,000 ft) Most common (T1): 1.5 Mbps down; 384 Kbps up

Line Splitter

Directs the traffic to phone network and DSL modem (aka DSL router)

Connecting to an ISP

Done through ISPs Point of Presence (POP) Done by individual or corporate users

HSPA+

Enhanced HSPA Reasonable bandwidth: 14.4 Mbps, 21 Mbps and 42Mbps are common Examples: T-Mobile, AT&T Bridge until LTE rollout is complete

Cell Sizes of LTE

Femtocells/picocells 100km macrocells 5km optimum for rural

Internet Research Task Force (IRTF)

Focus on long-term specific issues

VoLTE

GSM is circuit-switched VoLTE is packet-switched

Aggregate Internet Traffic

Growing rapidly In 2011, internet traffic was about 80 Tbps NAPs and MAEs are becoming bottlenecks that are requiring larger switches

Packet Exchange Charge: Peering

ISPs at the same level usually do not charge each other for exchanging messages

Cable Modems Offers vary (depends on the quality of cable plant)

In theory: downstream: 150 Mbps; upstream: 100 Mpbs Typical: downstream: 10+ Mbps; upstream 0.25 - 1 Mbps

Traditional Telephone Lines (local loop) portion of DSL:

Limited capacity due to telephone and switching equipment at the end offices Constrained by 4 KHz voice channel Much higher bandwidth possible (with new technology based equipment - DSL)

DSL Data Rates

Maximum Downstream Rate | Maximum Upstream Rate 1.5 Mbps | 384 Kbps 6 Mbps | 640 Kbps 12 Mbps | 1.5 Mbps 18 Mbps | 1.5 Mbps 24 Mbps | 3 Mbps

Asymmetric DSL (ADSL)

Most common Uses frequency division multiplexing Uses three FDM channels: 4 KHz analog voice channel, a simplex data channel for downstream traffic, and a slower duplex data channel for Upstream traffic

Data Over Cable Service Interface Specifications (DOCSIS)

Most common protocol used for cable modems Not a formal standard

Internet Access Technologies

Most methods today are commonly called "broadband access" - references high speed Digital Subscriber Line (DSL) Cable modems

LTE

Most mobile devices use ARM-based chips 2910.5 Mbps, 75.4 Mbps Spectrum Flexibility

The Internet

Most used network in the world Consists of thousands of networks Rigidly controlled club Unrestricted applications and contents

Networks the Internet Consists of:

National and State government agencies, non-profit organizations and for-profit companies

Internet's Access Points

Network Access Points (NAPs) Metropolitan Area Exchanges (MAEs)

Backbone circuits for national ISPs

OC-48 and OC-192 (10 Gbps): becoming more common Larger backbones converting to OC-192 (10 Gbps) OC-768 (40 Gbps) and use OC-3072 (160 Gbps): in experimental stage

Internet Society (ISOC)

Open membership professional society Over 175 organizational and 8000 individual members in over 100 countries Mission: "Open development, evolution and use of the Internet for the benefit of the people in the world."

Packet Exchange Charges

Peering Higher level ISPs charge lower level ISPs Tier 3 ISPs charge individuals and corporate users for access

Tier 1 Internet Service Providers (ISPs)

Provide services to their customers and sell access to tier 2 and 3 ISPs

Internet Architecture Board (IAB)

Provides strategic architectural oversight, guidance

ISOC work areas

Public policy: Involves in debates in copyright, censorship, privacy Education: Training and education programs Standards

Internet Engineering Steering Group (IESG)

Responsible for management of the standard process Establishes and administers rules in creating standards

Internet's Hierarchical Structure

Tier 1 Internet Service Providers (ISPs) Tier 2 ISPs Tier 3 ISPs

Internet Controls

To exchange data, these networks must agree to use Internet protocols TCP/IP must be supported by all networks

Connecting to an ISP as a corporate user:

Typically access the POP using a T-1, T-3 or ATM OC-3 connections provided by a common carrier Cost = ISP chargers + circuit charges

Connecting to an ISP as an individual:

Typically through cable or DSL The user ID and password are checked by Remote Access Servers (RAS) Once logged in, the user can send packets

Cable Modem Architecture

Use shared multipoint circuits: all messages on the circuit heard by all computers on the circuit (becomes a security issue) 300 - 1,000 customers per cable segment

Cable Modem Termination System (CMTS)

Used for upstream traffic only Converts data from DOCSIS to Internet protocols

WiMAX

Wireless standard developed to connect to Ethernet LANs Can be used as fixed or mobile wireless (4G) ISPs are beginning to provide this service and many mobile devices today use an Intel chip set PCF media access is used (controlled) 2.3, 2.5, and 3.5 GHz ranges Max range is 3-10 miles Common data rate is 40 Mbps