QCI (QoS Class Identifiers) Explained

Quality of service class identifiers (also called QCI values) indicate how traffic is handled on LTE networks.1 Without getting too technical, QCI values indicate a priority level for mobile traffic during periods of congestion.

Most data use is associated with QCI values between 6 and 9. In that range, lower QCI values are associated with higher priority service on a given network.

Some services, like voice calls and IMS signaling, may be associated with QCIs below 6. Sub-6 QCIs usually confer extra high priority and guaranteed bit rates. For a technical treatment of QCI values, see the 3GPP publication on Policy and charging control architecture.

Observed QCI Values

The lists below show QCI values observed with regular data use.2 An appendix includes additional information about when tests were run and who ran each test.3

Huge thanks to Stetson Doggett of BestPhonePlans.net for sharing a bunch of results.


AT&T’s Network

AT&T Postpaid:

  • Unlimited Starter – QCI 9
  • Unlimited Extra – QCI 8
  • Unlimited Elite – QCI 7

After running through my allotment of Premium Data on the Unlimited Extra plan, data use transitioned to being associated with a QCI of 9. I expect a similar transition occurs for subscribers on the Unlimited Elite plan.

AT&T Prepaid:

  • Unlimited Plus – QCI 8

Cricket wireless:

  • Limited-data plan – QCI 8
  • Unlimited More – QCI 9

Other

  • PureTalk – QCI 8

T-Mobile’s network

T-Mobile Postpaid:

  • Essentials – QCI 6
  • Magenta – QCI 6

T-Mobile Prepaid:

  • Connect – QCI 6

Google Fi:

  • Flexible – QCI 6
  • Simply Unlimited – QCI 6

Other:

  • Mint Mobile – QCI 7

Verizon’s network

Verizon:

  • Start Unlimited – QCI 9
  • Play More Unlimited – QCI 8
  • Do More Unlimited – QCI 8
  • Get More Unlimited – QCI 8

After running through my allotment of Premium Data on the Play More Unlimited plan, regular data use was associated with a QCI of 9. I expect the same transition occurs for subscribers on the Do More Unlimited and Get More Unlimited plans.


Xfinity Mobile:

  • Unlimited Intro – QCI 9
  • Unlimited Plus – QCI 9
  • Unlimited Premium – QCI 8
  • By-the-gig plans – QCI 8

Reported Online

Along with myself and Stetson, several folks have shred QCI test results online:

  • Boost (AT&T) – QCI 9 [claim]
  • Consumer Cellular – QCI 8 [claim]
  • PureTalk – QCI 8 [claim]
  • SafeLink (AT&T) – QCI 9 [claim]
  • Total Wireless – QCI 8 [claim]

Priority On Other Plans

Elsewhere, I share my expectations about a priority levels for a wider set of plans. My expectations draw on a combination of what I’ve learned from QCI tests, disclosures in legal documents, and conversations with industry experts.

Standardized QCI characteristics

The following table is a modified and abbreviated version of what appears in the 3GPP standards. Carriers may not always use QCI values is a way that’s entirely consistent with the standards.4

QCIResource TypePriority LevelPacket Delay BudgetPacket Error Loss RateExample Services
1Guaranteed Bit Rate (GBR)2100 ms10-2Conversational Voice
2GBR4150 ms10-3Conversational Video (Live Streaming)
3GBR350 ms10-3Real Time Gaming; V2X messages
4GBR5300 ms10-6Non-Conversational Video (Buffered Streaming)
65GBR0.775 ms10-2Mission Critical user plane Push To Talk voice (e.g., MCPTT)
66GBR2100 ms10-2Non-Mission-Critical user plane Push To Talk voice
67GBR1.5100 ms10-3Mission Critical Video user plane
75GBR2.550 ms10-2V2X messages
5Non-GBR1100 ms10-6IMS Signalling
6Non-GBR6300 ms10-6Video (Buffered Streaming); TCP-based (e.g., www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)
7Non-GBR7100 ms10-3Voice; Video (Live Streaming); Interactive Gaming
8Non-GBR8300 ms10-6Video (Buffered Streaming); TCP-based (e.g., www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)
9Non-GBR9300 ms10-6Same as above
69Non-GBR0.560 ms10-6Mission Critical delay sensitive signalling (e.g., MC-PTT signalling, MC Video signalling)
70Non-GBR5.5200 ms10-6Mission Critical Data (e.g. example services are the same as QCI 6/8/9)
79Non-GBR6.550 ms10-2V2X messages
80Non-GBR6.810 ms10-6Low latency eMBB applications (TCP/UDP-based); Augmented Reality

Further Notes On QCI Values

  • The consequences of a service’s QCI value will depend on the QCI values of other services operating on the same network. While a QCI of 7 appears to be indicative of high-priority data on AT&T’s network, a QCI of 7 appears to be indicative of relatively low-priority data on T-Mobile’s network.
  • Network operators might sometimes broadcast QCI values that aren’t accurate.5
  • I expect T-Mobile reserves a QCI of 8 for mobile hotspot use, but I haven’t confirmed that in a test.
  • A mechanisms similar to QCI values exists for 5G networks. I’m hoping to eventually update this page with more information about prioritization on 5G networks.

Appendix

Carriers using AT&T’s network (expanded)

AT&T

Unlimited Starter

I found a QCI of 9 for regular data use on AT&T’s Unlimited Starter plan on 8/31/2020.
Test result showing a QCI of 9

Stetson Doggett confirmed this result in 2021.

Unlimited Extra

I found a QCI of 8 for regular data use on the Unlimited Extra plan on 9/2/2020. Stetson Doggett confirmed this result in 2021. I ran the test when I had Premium Data available.
Test result showing a QCI of 8

On 11/11/2020, I ran a test when I no longer had Premium Data available. I found a QCI of 9 for regular data use.
Test result showing a QCI of 9

Unlimited Elite

I found a QCI of 7 for regular data use on the Unlimited Elite plan on 11/13/2020. I had Premium Data available when I ran the test.
QCI test showing a result of 7

Stetson Doggett confirmed this result in 2021.

Prepaid Unlimited Plus

In the middle of 2021, Stetson Doggett found a QCI of 8 on the Prepaid Unlimited Plus plan.

Cricket Wireless

I found a QCI of 8 for regular data use on a non-unlimited Cricket plan on 5/17/2020.

Test result showing a QCI of 8 on a non-unlimited Cricket Wireless plan

In 2021, Stetson Doggett confirmed this result and found a QCI of 9 on Cricket’s Unlimited More plan.

PureTalk

In May 2021, Stetson Doggett found a QCI of 8 with PureTalk. Reddit user u/uwroomitup corroborated in 2022. I don’t know what plan was used in either test.

Consumer Cellular

Reddit user u/uwroomitup found a QCI of 8 on an unknown plan in 2022.

Boost

Reddit user u/uwroomitup found a QCI of 9 on an unknown plan in 2022.

SafeLink

In early 2022, Reddit user Ethrem reported a QCI of 9 for SafeLink on AT&T’s network.

Carriers using T-Mobile’s network (expanded)

T-Mobile

Essentials

I found a QCI of 7 for regular data use on a T-Mobile Essentials plan on 9/3/2020.
Test result showing a QCI of 7

In October 2022, Stetson Doggett ran another test and found a QCI of 6.

Connect

I found a QCI value of 6 for regular data use on a T-Mobile Connect plan on 5/14/2020.

A test run on a T-Mobile Connect plan showing a QCI of 6

Magenta

I found a QCI value of 6 for regular data use on T-Mobile’s Magenta plan on 11/11/2020.

QCI test showing a QCI of 6

Magenta Plus

Stetson Doggett found a QCI of 6 on the Magenta Plus plan in late 2020. The Magenta Plus plan was replaced by Magenta MAX plan, so it’s not listed above. I expect the Magenta MAX plan is also QCI 6.

Mint Mobile

I found a QCI value of 7 for regular data use with Mint Mobile’s service on 9/17/2019.

Tello

Stetson Doggett found a QCI of 7 on a Tello plan in early 2021.

Google Fi

I found a QCI value of 6 for regular data use on Fi’s service on 9/17/2019.6

In April 2022, Stetson Doggett found a QCI of 6 with Fi’s Flexible plan. Around May 2022, he found a QCI of 6 on Fi’s Simply Unlimited plan.

Carriers using Verizon’s network (expanded)

Verizon

Start Unlimited

In early 2021, Stetson Doggett found a QCI of 9 on the Start Unlimited plan.

Play More Unlimited

I found a QCI of 8 for regular data use on the Play More Unlimited plan on 7/2/2020. I had not used up my Premium Data allowance when I ran the test.

Screenshot of a test result showing a QCI value of 8

After running through my Premium Data, I found a QCI of 9 on 7/3/2020.

QCI test result run after Premium Data allotment was used up. Screenshot shows a QCI of 9.

Do More Unlimited

I found a QCI of 8 for regular data use on the Do More Unlimited plan on 9/2/2020. I had Premium Data available when I ran the test.

Get More Unlimited

I found a QCI of 8 for regular data use on Verizon’s Get More Unlimited plan on 10/21/2020. I had Premium Data when I ran the test.

QCI test showing a QCI of 8

Total Wireless

I found a QCI of 9 for regular data use with Total Wireless on 6/2/2020.

QCI test for Total Wireless showing a QCI of 9

In 2021, @PATechUSA on Twitter suggested Total Wireless had moved to QCI 8.

Visible

Stetson Doggett found a QCI of 9 with Visible on 7/21/2020.

Test showing a QCI of 9

Xfinity Mobile

I found a QCI of 8 for regular data use on a third-generation by-the-gig plan on 7/3/2020.

Screenshot of a test result showing a QCI of 8 on a third-generation Xfinity Mobile by-the-gig plan

Stetson Doggett ran several tests around December 2022. He found a QCI of 8 for Xfinity’s Unlimited Premium plan and QCIs of 9 for Xfinity’s Intro and Plus plans.

Footnotes

  1. Other (often related) mechanisms include guaranteed bit rates, maximal bit rates, and allocation and retention priority. The excerpt below comes from page 51 of 3GPP TS 23.203 V16.1.0:
    “The service level (i.e., per SDF or per SDF aggregate) QoS parameters are QCI, ARP, GBR, and MBR.”
  2. When I say “regular data use,” I’m excluding voice calls, IMS signaling, and some atypical forms of data use.
  3. I share details about how QCI tests can be conducted on another page.

    If you’d like to contribute test results, please get in touch.

  4. Based on Table 6.1.7-A: Standardized QCI characteristics from 3GPP TS 23.203 V16.1.0.
  5. In a Reddit thread, user chrisprice suggested that some network operators broadcast QCI values that aren’t accurate. I think the user overstated his or her case and said some inaccurate things in the discussion, but I still take the possibility seriously. I’ve seen the same user demonstrate a deep understanding of the cellular industry in other conversations.

    The user chrisprice also raised the possibility that mechanisms other than QCI values may in some cases be used to manage traffic. An example involving AT&T dropping DNS links was shared in the discussion. I asked Roger Enter, an industry analyst, about the topic. He expressed skepticism about the idea that mechanisms other than QCI values are regularly used to prioritize traffic.

  6. I did this using a device that was compatible with Fi but not designated “Designed for Fi.”