May 2021 STIR/SHAKEN statistics

With the June 30 SHAKEN deadline rapidly approaching, we’ve looked at call statistics from our ClearIP customers to see whether they’re getting many calls that were signed using STIR/SHAKEN. We looked at similar statistics in March and April. Let’s have a look at what we found and what’s changed.

There are quite a few voice service providers using ClearIP to verify SHAKEN calls. This provides a good barometer of SHAKEN activity across the industry.

Verification statuses

What proportion of terminated calls were signed? Of the signed calls, were there any verification errors?

Verification statusMar–AprMayDifference
No PASSporT97.149131%93.624665%-3.524466%
Certificate chain error0.013079%0.100030%0.086951%
Called number mismatch0.001151%0.064497%0.063346%
Calling number mismatch0.003335%0.012633%0.009298%
Invalid info parameter in Identity header0.003049%0.001455%-0.001594%
Certificate repository error0.000280%0.000918%0.000638%
Invalid iat in PASSporT0.000052%0.000173%0.000121%
Invalid orig in PASSporT0.000033%0.000060%0.000027%


  • Of the calls received by ClearIP customers, more than 6% had a PASSporT. This is a significant improvement over March/April, where fewer than 3% had a PASSporT.
  • In March–April, 0.02% of signed calls generated verification errors. In May, 0.18% of signed calls generated verification errors. The error rates were small, but increased by a factor of 9.
  • Most of the PASSporTs with a verification status of Certificate chain error were signed with a self-signed certificate.
  • Most of the PASSporTs with a verification status of Called number mismatch had an invalid number in the dest claim of the PASSporT.
  • Most of the PASSporTs with a verification status of Calling number mismatch had a valid number in the orig claim of the PASSporT but had anonymous in the From and/or P-Asserted-Identity header.
bar chart

Attestation levels

What attestation levels are originating service providers using?

Attestation levelMar–AprMayDifference

Of the successfully verified calls received by ClearIP customers, more than 98% had an attestation level of A. This is nearly identical to what was seen in March/April.

SHAKEN participation by originating service provider

Which originating service providers are sending signed calls? Of all successfully verified calls received by ClearIP customers, which OSPs originated the most signed calls? (Note that these figures are the proportion of all successfully verified calls, not all calls.)

Originating Service Provider CodeLERG company nameCertificate repository domainMar–AprMay
5807CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NEsti.verizon.com0.995249%46.335284%
6529T-MOBILE USA, INC.cert.stir.t-mobile.com89.066747%46.221353%
1640ARMOUR INDEPENDENT TEL CO DBA GOLDEN WEST TELCOMMcertificates.clearip.com0.245363%1.037564%
1642ALLIANCE COMMUNICATIONS COOPERATIVE, INC. (BALTIC)certificates.clearip.com0.275487%0.617668%
1669TRIOTEL COMMUNICATIONS, INC.certificates.clearip.com0.060708%0.433753%
1680VENTURE COMMUNICATIONS COOPERATIVEcertificates.clearip.com0.028055%0.410939%
5606CHARTER FIBERLINK CCO, LLCshaken.spectrum.com0.310023%
551GBRIGHTLINK COMMUNICATIONS, LLCcertificates.transnexus.com0.800476%0.297846%
583jBROADBAND DYNAMICS, LLCcr.sansay.com0.161429%0.201830%
599JTECHNOLOGY INNOVATION LAB LLCcertificates.clearip.com0.002070%0.184754%
1676SANTEL COMMUNICATIONS COOPERATIVE, INC.-SDcertificates.clearip.com0.181115%
502JPIRATEL LLCcertificates.piratel.com0.157290%0.071522%
1674RC TECHNOLOGIEScertificates.clearip.com0.064384%
073HTELNYX LLCcertificates.transnexus.com0.069677%0.056126%
996HAIRESPRING INCcr.sansay.com0.034711%
7804TDS METROCOM INC. - WIsti-cr.cgah.tnsi.com0.029953%
696J cr.sansay.com0.029813%
1649BERESFORD MUNICIPAL TELEPHONE CO.certificates.clearip.com0.027713%
363AIDT AMERICA CORPORATIONcr.sansay.com0.001380%0.020715%
0546SANDHILL TELEPHONE COOPERATIVE, INC.certificates.clearip.com0.000230%0.019175%
324EYMAX COMMUNICATIONS CORP. - NVsns.magicjack.com0.037023%0.018196%
6349UNITED STATES CELLULAR CORP. - OREGONcrs.sti.uscellular.com0.017076%
745BCROCKER TELECOMMUNICATIONS, LLC - MAcertificates.clearip.com0.011617%
5113CONSOLIDATED COMM OF NO. NEW ENGLAND-NHcr.sansay.com0.017017%0.005739%
0127WINN TELEPHONE COMPANY DBA WINN TELECOM - MIcertificates.clearip.com0.000460%0.004479%
1653CITY OF FAITH MUNICIPAL TELEPHONE CO.certificates.clearip.com0.004339%
548JQUALITY VOICE & DATA INCcertificates.clearip.com0.020006%0.002379%
469AT3 COMMUNICATIONS, INC. - FLcertificates.clearip.com0.005059%0.002379%
997EBANDWIDTH.COM CLEC, LLC - NYbw-shaken-cert-pub.s3.amazonaws.com0.001540%
727J certificates.clearip.com0.001540%
7615RCN TELECOM SERVICE OF PENNSYLVANIA, INC.sti-cr.cgah.tnsi.com0.001120%
610JMULTITEL LLCcertificates.clearip.com0.000460%0.001120%
7459HANCOCK COMMUNICATIONS, INC. - INcertificates.clearip.com0.001840%0.000980%
8812SOUTH DAKOTA NETWORK, LLCcertificates.clearip.com0.000980%
1088WABASH TELEPHONE COOPERATIVE, INC.certificates.clearip.com0.000840%
672BCLEAR RATE COMMUNICATIONS - ULEC - MIcertificates.clearip.com0.010578%0.000840%
691ADAYSTARR, LLC DBA DAYSTARR COMMUNICATIONS - MIcertificates.clearip.com0.000700%
9107DIGITAL AGENT, LLC - GAcertificates.clearip.com0.000700%
2116MUENSTER TELEPHONE CORP. OF TEXAS DBA NORTEX COMMcertificates.clearip.com0.000280%
700HMETRO FIBERNET, LLCcertificates.clearip.com0.000140%
366GUSA DIGITAL COMMUNICATIONS, INC.certificates.clearip.com0.000140%
495JSTRATUS NETWORKScertificates.clearip.com0.000140%

We went from 26 originating service providers that sent signed traffic in March/April to 50 in May. New participants do not have a number in the March column. It’s s a big jump, but we expected more so close to the June 30 deadline.

Because access to numbers is no longer a requirement to receive and Service Provider Code token, some Service Provider Codes are not in the LERG. We left the LERG company name blank for those providers in this table.

Note that the above data reflects both call volume and SHAKEN activity. The data shows the proportion of successfully verified calls received by ClearIP customers for each originating service provider as a percentage of all successfully verified calls.

If a small number of calls were received from an originating service provider, then percentage of successfully verified calls received by ClearIP customers would be low, even if the originating service provider signed a high percentage of their outbound calls.

The above data includes only originating service providers that had at least one successfuly verified call received by a ClearIP customer.

Certificate repositories

What are typical certificate latencies, i.e., time-to-fetch, and why? This was one of the most surprising results in the March/April statistics, and it continues to this day. Several Certificate Repositories are adding significant latency and post dial delay to calls because they are not set up to use cache control.

Certificate repository domainCache hit percentageAverage latency including cache hits (milliseconds)Average latency excluding cache hits (milliseconds)Cache-Control header time (seconds)

Retrieving a certificate from a certificate repository takes time, or latency, which increases Post-Dial Delay (PDD). If a certificate is cached by the STI-VS, then it does not need to be retrieved.

A certificate repository can be configured to provide a Cache-Control HTTP header, which tells the STI-VS how long to cache the certificate after retrieving it. If a certificate repository does not provide the Cache-Control header, the STI-VS does not cache the certificate or caches the certificate for only a short time.

Note that the ClearIP STI-VS caches certificates for 60 minutes if the Cache-Control header is not set by the certificate repository or if the Cache-Control header contains a value of less than 60 minutes.


  • More than 6% of calls were signed. This is a significant improvement over March/April, where fewer than 3% had a PASSporT.
  • Fewer than 3% of signed calls had verification errors. This is significantly higher than March/April. The vast majority of the signed calls with verification errors were due to self-signed certificates.
  • More than 98% of successfully verified calls had an attestation level of A. This is nearly identical to what was seen in March/April.
  • Successfully verified calls were received from 50 originating service providers. This is almost double the number of unique Service Provider Codes seen during March/April.
  • More than 55% of certificate repositories did not include the Cache-Control header. This is slightly lower than March/April.

TransNexus solutions

We offer STIR/SHAKEN and robocall mitigation solutions in our ClearIP and NexOSS software platforms. We can make your STIR/SHAKEN deployment a smooth process.

In addition, we help service providers with all aspects of STIR/SHAKEN deployment, including registering with the Policy Administrator and filing their certification with the FCC.

Contact us today to learn more.

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