Measuring Broadband America Fixed Report - 2015

2015
Measuring Broadband America
Fixed Broadband Report

A Report on Consumer Fixed Broadband Performance
in the United States

FCC's Office of Engineering and Technology
and
Consumer and Governmental Affairs Bureau

Table of Contents

• Executive Summary
• Summary of Key Findings  
  • Most popular advertised service tiers
  • Actual download speeds
  • Variations in speeds
  • Latency
  • Packet loss
  • Web Browsing Performance
• Methodology  
  • Participants
  • Measurement process
  • Measurement tests and performance metrics
  • Availability of Data
• Test Results  
  • Most popular advertised service tiers
  • Actual speeds
  • Variations in speeds
  • Latency
• Additional test results  
  • Actual speed, by service tier
  • Variations in speed
  • Web browsing performance, by service tier
  • Methodology and Sampling Plan for Statewide Statistics
• Appendix A: AT&T Separation of IP-based U-verse from ATM-based DSL

Executive Summary

The 2015 Measuring Broadband America Fixed Broadband Report (“2015 Report”) contains the most recent data collected from fixed Internet Service Providers (ISPs) as part of the Federal Communication Commission’s (FCC) Measuring Broadband America program.  This program is an ongoing, rigorous, nationwide study of consumer broadband performance in the United States.  We measure the network performance delivered on selected service tiers to a representative sample set of the population.  The thousands of volunteer sample panelists are drawn from subscribers of Internet Service Providers (ISPs) serving over 80% of the residential marketplace. 

The initial Measuring Broadband America Fixed Broadband Report was published in August 2011, and presented the first broad-scale study of directly measured consumer broadband performance throughout the United States.  Including the 2015 Report, five reports have now been issued.[1]  These annual reports provide a performance benchmark for fixed broadband Internet access services in the United States, and track progress towards the Commission’s continuing goal of improving the speeds and quality of broadband access commonly available to the American public.

In order to better inform consumers about the potential variability of their broadband service performance, the 2015 Report expands our prior analysis of the consistency of service delivered to the consumer.  The 2015 Report also introduces multi-year and regional views of performance.  These new regional statistics help show how performance measured in this study varies across the US and what portion of the program’s sample panelists within the United States are reaching the FCC’s new 25 Mbps definition of broadband service.  These new charts inform consumers about the consistency in performance of broadband services and show high level performance trends for technologies, service tiers, and geographic areas.

We continue to see significant growth in broadband speeds and in the uptake of these higher speeds by consumers, though results are not uniform across technologies.  Spurred by the deployment of enabling technologies such as DOCSIS 3, the maximum advertised download speeds among the most popular service tiers offered by ISPs using cable technologies has increased from 12-30 Mbps in March 2011 to 50-105 Mbps in September 2014. In contrast, the maximum advertised download speeds that SamKnows tested among the most popular service tiers offered by ISPs using DSL technology has remained generally unchanged since 2011. There is a growing disparity in most download speeds tested between many DSL-based broadband services and most cable-based broadband services.[2]

As in our most recent reports, we find that the actual speeds experienced by most ISPs’ subscribers are close to or exceed the advertised speeds.  All ISPs using cable, fiber or satellite technologies advertise speeds for services that on average are close to or below the actual speeds experienced by their subscribers.  However, some ISPs using DSL technologies continue to advertise “up-to” speeds that on average exceed the actual speeds experienced by their subscribers.

Actual speeds experienced by consumers may vary based on location and may vary during each day.  Starting in this report, we now illustrate, for each ISP, the percentage of participating consumers who experienced an actual monthly average download speed that was greater than 95%, between 80% and 95%, and less than 80% of the advertised download speed.  Even though the actual download speeds experienced by most ISPs’ subscribers are close to or exceed the advertised download speeds, for each ISP there are some panelists for whom actual download speed falls significantly short of the advertised download speed. Relatively few subscribers to cable, fiber, or satellite broadband service experience such shortfalls.

Consistency of speed may be more important to customers who are heavy users of applications that are both high bandwidth and sensitive to variations in actual speed, such as streaming video.[3]  In this Report, we continue to present statistics on the minimum actual speed that was experienced by at least 80% of panelists during at least 80% of the peak usage period. 

Although actual download and upload speeds remain the network performance metric of greatest interest to the consumer, we spotlight two other key network performance metrics in this report: latency and packet loss. 

Latency may affect the perceived quality of highly interactive applications such as phone calls over the Internet, video chat, or online multiplayer games.  The higher latencies of satellite-based broadband services may negatively affect the perceived quality of such highly interactive applications.  However, the differences in average latencies among terrestrial-based broadband services are small, and are unlikely to affect the perceived quality of such highly interactive applications.  Furthermore, differences in average latencies across all technologies are unlikely to affect less interactive applications such as web browsing and video streaming.

Packet loss may affect the perceived quality of applications that do not request retransmission of lost packets, such as phone calls over the Internet, video chat, some online multiplayer games, and some video streaming.  However, packet losses of a few tenths of a percent are sufficiently small so that they are unlikely to significantly affect the perceived quality of most such applications.  Packet losses closer to one percent may affect the perceived quality of some such applications, depending on how the application responds to the packet loss.  Packet loss is unlikely to directly affect the perceived quality of applications that do request retransmission of lost packets, such as web browsing and email.

The Internet is continuing to evolve along multiple dimensions: architecture, performance, and services.  We will continue to evolve our measurement methodologies to help consumers understand the performance characteristics of their broadband Internet access service, and to thus make informed choices about their use of such services.   

Summary of Key Findings

A.      Most popular advertised service tiers

As explained in more detail in the section on Methodology below, these reports focus on the most popular service tiers offered by each participating ISP, as shown in Table 1, which together constitute the majority of the broadband plans subscribed to by their consumers.  Some participating ISPs also offer faster service tiers than shown here, but if their number of subscribers is small, they are not analyzed herein.[4]

Table 1: The most popular advertised service tiers

Chart 1 (below) displays the maximum advertised download speeds among the most popular service tiers for each participating ISP, during the years 2011-2014, grouped by the access technology used to offer the broadband Internet access service (DSL, cable, fiber and satellite).  Between September 2013 and September 2014, we observe a 105% increase in the maximum advertised download speeds among the most popular service tiers across participating ISPs weighted by the number of participants using a given ISP; this increase is not uniform across access technologies.

Chart 1 shows that when DSL is used to provide broadband service, the maximum advertised download speeds among the most popular service tiers has remained generally unchanged since 2011.[5]  In contrast, when cable is used to provide broadband service, the maximum advertised download speeds among the most popular service tiers has increased from 12-30 Mbps in March 2011 to 50 - 105 Mbps in September 2014.[6]  In particular, most cable broadband ISPs now offer a 50 Mbps or 100 Mbps download speed tier, taking advantage of the increase in download speeds made possible by the transition from DOCSIS 2 to DOCSIS 3 technology.[7]

Chart 1: Maximum advertised download speed among the most popular service tiers

Among participating broadband ISPs, only Frontier and Verizon use fiber as the access technology for a substantial number of their customers. While the maximum download speed measured by SamKnows for Frontier's fiber product has remained 25 Mbps throughout the couChart 1.51rse of these Reports, the maximum popular download speed included in our survey for Verizon has more than doubled from 35 Mbps to 75 Mbps in 2012 and has remained at that speed in subsequent years.

We report results for ViaSat (Exede) starting September 2012 and for Hughes starting September 2014, representing when each began its respective participation in the program.

The maximum advertised download speed among the most popular service tiers, averaged across all participating ISPs (weighted by the number of panelists) increased from 37.2 Mbps in September 2013 to 72.0 Mbps in September 2014, an increase of 94%.  However as noted, this increase in advertised download speed is not uniform across access technologies. 

Chart 2 charts the migration of panelists to a higher tier based on their access technology[8].  Specifically, the horizontal axis of Chart 2 partitions the September 2013 panelists by the advertised download speed of the service tier to which they are subscribed.  For each such set of panelists who also participated in the September 2014 collection of data[9], the vertical axis of Chart 2 displays the percentage of panelists that migrated by September 2014 to a service tier with a higher advertised download speed.  There are two ways that such a migration can occur: (1) if a panelist changed their broadband plan during the intervening year to a service tier with a higher advertised download speed, or (2) if a panelist did not change their broadband plan but the panelist’s ISP increased the advertised download speed of the panelist’s subscribed plan.[10]

Chart 2 shows that among panelists subscribed in September 2013 to service tiers with advertised download speeds less than 15 Mbps, only a few percent migrated within the following year to a service tier with a higher advertised download speed.  In contrast, among panelists subscribed in September 2013 to service tiers with advertised download speeds between 15 Mbps and 30 Mbps, there was a much higher rate of migration within the following year to a service tier with a higher advertised download speed.  This observation is consistent with the observations above regarding the maximum advertised download speeds of each access technology.  Generally, speed tiers at 15 Mbps and below are dominated by DSL, while speed tiers above 15 Mbps are dominated by cable and fiber. 

Chart 2: Consumer migration to higher advertised download speeds

B. Actual download speeds

Advertised download speeds may differ from that actually experienced by subscribers; this can be the case for several reasons.  First, each ISP chooses what speed to advertise, and their decisions may vary.  Second, speeds experienced by different consumers subscribed to the same ISP and the same service tier may vary across a geographical region based on the subscriber’s location.  Third, speeds experienced by a particular consumer will vary during the day based on variations in the aggregate Internet usage by all subscribers to that consumer’s ISP.  We examine each of these factors in turn.  Unless stated otherwise, all actual speeds are measured only during peak usage periods.

Chart 3 shows the actual download speeds experienced by each participating ISP’s subscribers -- averaged across all analyzed speed tiers, geography, and time -- from 2011 to 2014.  The actual download speed, averaged across all participating ISPs, has tripled during this period, from approximately 10 Mbps in March 2011, to approximately 15 Mbps in September 2012, to nearly 31 Mbps in September 2014. 

Chart 3: Actual download speeds by ISP, 2011 to 2014

However, as we observed above when examining advertised download speeds, the increase in actual download speeds is not uniform across access technologies.  For subscribers to DSL-based broadband service, the increase in actual download speeds has varied among ISPs.  For subscribers to each of the participating cable broadband services, there have been fairly steady and substantial increases in actual download speeds.[11]  We find that, over the course of our reports, the average annual increase in actual download speeds by technology has been 28.2% for DSL[12], 61.2% for cable, and 19.2% for fiber[13].

Chart 4 shows the ratio in September 2014 of the actual speeds experienced by an ISP’s subscribers (averaged across both geography and time) to that ISP’s advertised speeds.[14]  The ratios for downloads and uploads are both illustrated.  The ratio in September 2014 of the actual download speeds to advertised download speeds, averaged across all panelists, was 105.6%, an increase from the 101.6% reported last year for September 2013.[15]  For uploads, the similar ratio increased to 113.2% compared to the previous year’s 109.1%.

The actual speeds experienced by most ISPs’ subscribers (when averaged across both geography and time) are close to or exceed the advertised speeds.  However, some DSL broadband ISPs continue to advertise “up-to” speeds that on average exceed the actual speeds experienced by their subscribers. 

Chart 4: The ratio of actual speed to advertised speed

C.      Variations in speeds

As noted above, actual speeds experienced by consumers may vary based on location and may vary during each day.  Chart 5 shows, for each ISP, the percentage of consumers (across the ISP’s service territory) who experienced an actual download speed (averaged over the peak usage period during our measurement period) that was (a) greater than 95%, (b) between 80% and 95%, and (c) less than 80% of the advertised download speed.

Chart 5: The percentage of consumers whose actual download speed was (a) greater than 95%, (b) between 80% and 95%, and (c) less than 80% of the advertised download speed

Even though the actual download speeds experienced by most ISPs’ subscribers (when averaged across both geography and time) are close to or exceed the advertised download speeds, for each ISP there are some panelists for whom actual download speed falls significantly short of the advertised download speed.  Relatively few subscribers to cable, fiber, or satellite broadband service experience such shortfalls.  The best performing ISPs, when measured by this metric, are Cablevision, Comcast, and Hughes; fewer than 10% of each their panelists were unable to attain an actual average download speed of at least 95% of the advertised download speed.  In contrast, many subscribers to some ISPs’ DSL broadband service experience actual download speeds that fall substantially short of advertised download speeds. 

In addition to variation based on a subscriber’s location, speeds experienced by a particular consumer will vary during the day based on variations in aggregate usage by all subscribers to that consumer’s ISP.  For purposes of discussion, we use the term “80/80 consistent speed” to refer to the minimum actual speed that was experienced by at least 80% of panelists during at least 80% of the peak usage period.  Consistency of speed may be more important to customers who are heavy users of applications that are both high bandwidth and sensitive to variations in actual speed.[16]

Chart 6 illustrates, for each ISP, the ratio of 80/80 consistent download speed to advertised download speed, and for reference the ratio of actual download speed to advertised download speed shown previously in Chart 4.  The ratio of 80/80 consistent download speed to advertised download speed is less than the ratio of actual download speed to advertised download speed for all participating ISPs, due to fluctuations in Internet usage that occasionally result in short periods of time when actual download speeds are lower than the overall average.  When the difference between the two ratios is small, the actual download speed is fairly insensitive to both geography and time.  When the difference between the two ratios is large, there is a greater variability in actual download speed, either based on location or variations during the peak usage period.

Chart 6: The ratio of 80/80 consistent download speed to advertised download speed.

Customers of Cablevision, Comcast, or Verizon Fiber (FiOS) experienced actual download speeds that are very consistent; over 80% of their customers experienced actual download speeds at or above advertised download speeds during at least 80% of the peak usage period.  Hughes customers, in contrast, experienced actual download speeds that are highly variable; however, since Hughes advertises conservative download speeds, over 80% of Hughes customers also experienced actual download speeds at or above advertised download speeds during at least 80% of the peak usage period.

In contrast, there are a few ISPs who offer service for which consistent download speed falls substantially short of their advertised download speed, even though the actual download speed (averaged over geography and time) may meet or exceed the advertised download speed.  Finally, as we observed above, some DSL broadband ISPs’ actual download speed falls substantially short of their advertised download speed; the gap between their consistent download speed and advertised download speed is even greater.

D. Latency

Latency is the time it takes for a data packet to travel from one point to another in a network.  It increases with distance of the route between the source and destination and with any congestion on the route, and decreases as actual speed increases.  The Measuring Broadband America program measures latency by measuring the round-trip time from the consumer’s home to the closest measurement server and back.

Chart 7 shows the average latency for each participating ISP.  The data suggest that average latency is strongly influenced by the technology used by the ISP.  In particular, satellite-based broadband service transmits packets to and from the consumer through a satellite.  As a consequence, the distances of the paths used by satellite-based broadband services are much higher than those used by terrestrial technologies (DSL, cable, and fiber), and the average latencies of satellite-based broadband services (which range from 603 ms to 659 ms) are much higher than those for terrestrial-based broadband services (which range from 14 ms to 52 ms).

Chart 7: Latency by ISP

(a)    Terrestrial ISPs

(b)   Satellite ISPs

Latency may directly affect the perceived quality of highly interactive applications such as phone calls over the Internet, video chat, or online multiplayer games.  The higher latencies of satellite-based broadband services may negatively affect the perceived quality of such highly interactive applications.  However, the differences in average latencies among terrestrial-based broadband services are small, and are unlikely to affect the perceived quality of such highly interactive applications.

These differences in average latencies are unlikely to affect less interactive applications such as web browsing and video streaming, except for creating indirect effects on actual speed.  Latency may indirectly affect the actual speed of the service due to its impact on Transmission Control Protocol (TCP), the software protocol commonly used to control the transport of information on the Internet.  However, this effect may be more directly observed by considering the actual speed observed by consumers of a particular ISP at a particular service tier.

E. Packet loss

Packet loss is the percentage of packets that are sent by the source but not received by the destination.  The most common reason that a packet is not received is that it encountered congestion along the route.  A small amount of packet loss is expected, and indeed some Internet protocols use the packet loss to understand Internet congestion and to adjust the sending rate accordingly. The Measuring Broadband America program denotes a packet as lost if the latency exceeds 3 seconds or if the packet is never received.

Chart 8 shows the average packet loss for each participating ISP, grouped by technology.

Chart 8:  Packet loss by ISP

Packet loss may directly affect the perceived quality of applications that do not request retransmission of lost packets, such as phone calls over the Internet, video chat, some online multiplayer games, and some video streaming.  However, packet losses of a few tenths of a percent are sufficiently small so that they are unlikely to significantly affect the perceived quality of most such applications.  Packet losses closer to one percent may affect the perceived quality of some such applications, depending on how the application responds to the packet loss.

Packet loss is unlikely to directly affect the perceived quality of applications that do request retransmission of lost packets, such as web browsing and email, except for creating indirect effects on actual speed.  Packet loss may indirectly affect the actual speed of the service due to its impact on TCP.  However, this effect may be more directly observed by considering the actual speed observed by consumers of a particular ISP at a particular service tier.

F. Web Browsing Performance

The Measuring Broadband America program also conducts a specific test to gauge web browsing performance.

The web browsing test accesses 9 popular websites that include text and images, but not streaming video.  The time required to download a webpage depends on many factors, including a consumer’s actual download speed within an ISP’s network, the web server’s speed, congestion in other networks outside the consumer’s ISP’s network (if any), and the time required to identify the location of the webserver.  Of all of these factors, only the actual download speed within an ISP’s network is within the control of the consumer’s ISP.  Chart 9 displays the average webpage download time by the advertised download speed.  Users subscribing to a service tier with a 1.5 Mbps download speed on average wait for approximately 7.5 seconds for a webpage containing text and images; users subscribing to a service tier with a 5 Mbps download speed on average wait only approximately 2.5 seconds; and users subscribing to a service tier with a 25 Mbps download speed on average wait on only approximately 1 second.  Subscribers to service tiers with an advertised download speed exceeding 25 Mbps on average do not experience significantly reduced webpage download time.  These download times assume that a single user is using the Internet connection at the time at which the webpage is downloaded, and does not account for more typical scenarios where multiple users within a household are simultaneously using the Internet connection for multiple uses, such as real-time gaming or video streaming.

Chart 9: Average webpage download time, by advertised download speed

 

Methodology

A.      Participants

Thirteen ISPs participated in the Fixed Measuring Broadband America program in September 2014.[17]  They are:

• AT&T
• Cablevision Systems Corporation
• CenturyLink
• Charter Communications
• Comcast
• Cox Communications
• Frontier Communications Company
• Hughes Network Systems
• Mediacom Communications Corporation
• Time Warner Cable
• Verizon
• ViaSat
• Windstream Communications

The methodologies and assumptions underlying the measurements described in this Report are reviewed at meetings that are open to all interested parties, and documented in public ex parte letters filed in the GN Docket No. 12-264.  Participation in this effort is open and voluntary.  In 2014-2015, participants at these meetings (collectively and informally referred to as “the broadband collaborative”), included all thirteen participating ISPs and the following additional organizations:

• Adtran
• Corning
• Fiber to the Home Council
• Georgia Institute of Technology
• Genband
• Intel
• Internet Society
• JDSU
• Level 3 Communications (¿Level 3¿)
• Massachusetts Institute of Technology (¿MIT¿)
• M-Lab
• Motorola
• National Cable & Telecommunications Association (¿NCTA¿)
• New America Foundation
• Practicum Team, NCSU, Institute for Advanced Analytics
• United States Telecom Association (¿US Telecom¿)

Participants have contributed importantly to the integrity of this program.  Initial proposals for test metrics and testing platforms were discussed and critiqued within the broadband collaborative.  M-Lab and Level 3 contributed their core network testing infrastructure, and both parties continue to provide invaluable assistance in helping to define and implement the FCC testing platform.  Policy decisions regarding our program involving such things as test periods, mitigation of operational issues, terms of use notifications to panelists, etc. are discussed at these meetings prior to adoption.  Participation in these discussions from diverse groups representing academia, consumer equipment vendors, telecommunications vendors, network service providers, consumer policy advocates as well as our contractor for this project, SamKnows, provide valuable feedback for FCC decisions on the deployment and ongoing management of this program.  We wish to thank the participants for their contributions to this program.

B. Measurement process

The measurements that provide the underlying data in this Report rely both on measurement clients and measurement servers.  The measurement clients reside in the homes of 5,583 panelists who receive service by the 13 participating ISPs.  The participating ISPs collectively account for over 80% of U.S. residential broadband Internet connections.  The panelists closely match the overall state and region statistics of Internet access connections in the United States as reflected in the Commission’s Form 477 data.[18]

The measurement servers are hosted by M-Lab and Level 3 Communications, and are located in 9 cities across the United States near a point of interconnection between the ISP’s network and the network on which the measurement server resides.[19]

The measurement clients collect data throughout the year, and this data is available as described below.  However, only data collected from September 1, 2014 to September 16, 2014 and from September 27, 2014 to October 11, 2014 (referred to throughout this report as the “September 2014” reporting period) are used to generate the charts in this Report.[20]

One of the key factors affecting all aspects of broadband performance is the time of day.  At peak hours more people are attempting to use their broadband Internet connections, giving rise to a greater potential for congestion and degraded user performance.  Unless otherwise stated, this Report focuses on performance during peak usage period, which is defined as weeknights between 7:00 PM to 11:00 PM local time.  Focusing on peak usage period provides the most useful information because it demonstrates the performance users can expect when the Internet in their local area is experiencing highest demand from users.

Although the Report generally focuses on each participating ISP’s entire service territory, in this Report we also briefly analyze network performance in each of the four census regions of the United States.[21]    

Our methodology focuses on performance within each participating ISP’s network.  The metrics discussed in this Report are derived from traffic flowing between a measurement client (located within the modem or router within a panelist’s home) and a measurement server.  For each panelist, the tests use the measurement server for which the latency between the measurement client and server is the lowest.  As a result, the metrics measure congestion (if any) within each ISP’s network, as well as congestion (if any) at a point of interconnection between the ISP’s network and the network on which the measurement server resides; however, since each panelist’s tests rely on a single measurement server, the metrics will only measure congestion (if any) at a single point of interconnection. 

However, the performance that a consumer may experience may differ for at least three reasons.  First, a consumer may be communicating with a point on the Internet that is outside the network of the consumer’s ISP.  There may be congestion in a portion of the Internet along the route that is outside the network of the consumer’s ISP; the effects of this congestion on the user experience is not reflected in the data set forth in this Report.  Second, a consumer’s home network may be the bottleneck, rather than the ISP’s network.  This may occur, for instance, if the home network’s maximum transmission rate is lower than the advertised speed of the selected service tier; if a device is communicating with a Wi-Fi home router at a reduced speed due to walls or obstructions in between the device and the router; if multiple users within the home are currently sharing the total actual speed available; or if there is congestion within the home network due to transfers of data within the home.  Third, consumers typically view performance through the lens of a set of applications that they utilize.  The performance as seen through a particular application depends on both the network performance and on the application performance.  While network performance is considered in this Report, application performance is generally not.  For instance, if a consumer is web-browsing, the delay from a request for a webpage to the display of that webpage includes network latency (considered in this Report), the time it takes for the webserver to respond to the request, and the time it takes for the browser to render that webpage.  The latter two components of the total delay are only considered in the Web Browsing test.  For other commonly used applications, this Report does not consider components of the application performance that are outside the control of the ISP.

C. Measurement tests and performance metrics

This Report is based on the following measurement tests:

·         Download speed: Measures the download speed over a 5 second time interval, every 2 hours; the results are then averaged to determine the “actual download speed” for each panelist.

·         Upload speed: Measures the upload speed over a 5 second time interval, every 2 hours; the results are then averaged to determine the “actual upload speed” for each panelist.

·         Latency and packet loss: Measures the round-trip times for packets sent at randomly distributed times.  Times less than 3 seconds are averaged to determine “average latency”. Acknowledgements not received or received with a round-trip time greater than 3 seconds determine “packet loss”.

·         Web browsing: Measures the total time to request and receive webpages (including the text and images on each webpage) from 9 popular websites, every hour.  The measurement includes the time required to translate the webpage name into the webserver’s IP address.

The Measuring Broadband America program also runs three tests that are not used in this Report, but for which data is available as described in section 2.D.

This Report focuses on three performance metrics that are of particular relevance to consumers of broadband Internet access service: speed, latency, and packet loss.  Download and upload speeds are the primary network performance characteristic advertised by ISPs.  Actual download speed is the average rate at which information can be downloaded by the consumer.  Higher speeds indicate a higher delivery rate.  However, as discussed above, the performance observed by a user in any given circumstance depends not only on the actual speed of the ISP’s network, but also on the speed of other parts of the Internet and on the speed of the application itself.[22]

Latency is the time it takes for a data packet to travel from one point to another in a network.  It increases with distance of the route or path between the source and destination and with any congestion on the route.  The Measuring Broadband America program measures the round-trip time between the consumer’s home and the closest measurement server.  Latency may directly affect the perceived quality of highly interactive applications, such as real-time two-way voice applications,[23] video chat, or interactive games.  Latency may also indirectly affect actual speed.  Some applications consist of a sequence of network tasks, so the effect of network latencies may accumulate.

Packet loss is the percentage of packets that are sent by the source but not received by the destination.  The most common reason for packet loss is that the packet encountered congestion along the route.  A small amount of packet loss is expected, and indeed some Internet protocols use packet loss to understand network congestion, and adjust the sending rate accordingly.  The Measuring Broadband America program denotes a packet as lost if the latency exceeds 3 seconds or if the packet is never received.

The Technical Appendix for the 2015 Report provides specific information regarding the process by which measurements were made and describes each test that was performed.

D.      Availability of Data

The Validated Data Set[24] on which this Report was based, as well as the full results of all tests, are available at http://www.fcc.gov/measuring-broadband-america. 

In addition to the Validated Data Set for the September 2014 reference month, in the interest of transparency and to support additional research, raw data for the reference month as well as other months is available at the same website.  Previous reports of the Measuring Broadband America program, as well as the data used to produce them, are also available at the same website.

Both the Commission and SamKnows, the Commission’s contractor for this program, recognize that, while the methodology descriptions included in this document provide an overview of the project as a whole, there will be a number of interested parties – ranging from recognized experts to members of the general public – who would be willing to contribute to the project by reviewing the actual software used in the testing.  SamKnows welcomes review of its software and technical platform, consistent with the Commission’s goals of openness and transparency for this program.[25]

Chart 21.2: The ratio of actual download speed to advertised download speed, by ISP (6-10 Mbps)

Chart 21.3: The ratio of actual download speed to advertised download speed, by ISP (12-15 Mbps)

Chart 21.4: The ratio of actual download speed to advertised download speed, by ISP (18-25 Mbps)

Chart 21.5: The ratio of actual download speed to advertised download speed, by ISP (30-50 Mbps)

Chart 21.6: The ratio of actual download speed to advertised download speed, by ISP (60-105 Mbps)

Charts 22.1 –22.5 depict the ratio of actual upload speeds to advertised upload speeds for each ISP by service tier.

Chart 22.1: The ratio of actual upload speed to advertised upload speed, by ISP (0.256-0.64 Mbps)

Chart 22.2: The ratio of actual upload speed to advertised upload speed, by ISP (0.768-1.5 Mbps)