Advertising watchdog ASCI has found Bharti Airtel 's advertisement claiming it to be "officially" fastest network misleading and has asked the telco to modify or withdraw the commercial by April 11.Bharti Airtel, however, has contested the findings.Upholding the complaint filed by rival Reliance Jio Infocom, the Advertising Standards Council of India (ASCI) said that TVC was "misleading" and "contravened Chapters" of its Code as well as guidelines on disclaimers clauses."We have advised the advertiser to modify appropriately or to withdraw the said TVC and the website advertisement by April 11, 2017," ASCI said in its order.Rejecting the findings of the Fast Track Complaints Committee (FTCC) of ASCI, Bharti Airtel said it would file an appeal against it."We do not agree with ASCI's decision and will file an appeal as per guidelines," Bharti Airtel said in a statement."Our campaign is based on findings by Ookla - the globally recognised leader in mobile speed tests and also a benchmark for reputed global operators. We have shared all supporting facts with ASCI and strongly believe that our campaign is compliant with all guidelines. We will be happy to provide more details, if required, and hope ASCI will reconsider its decision," the country's largest telecom firm said.Bharti Airtel has come out with TVC claiming to be India's fastest network based on Ookla's finding. Rival Reliance Jio contested the claim and moved the ad regulator against the commercial.Ookla too responded to ASCI decision saying that it fully stands behind the accuracy and reliability of the methodology used to designate Airtel as 'India's Fastest Mobile Network'.The ASCI committee observed that "the TVC does not state in the claim itself that the speed results pertain to only a specific period which was July-December 2016.Besides awarding Airtel as the fastest for third and the fourth quarter of 2016, Ookla said that the telecom major is still the fastest mobile network."When analyzing data for 2017 to date, Airtel is still the clear leader. It is worth noting that after correcting for the Android limitation, Airtel's lead over Jio increases for all aforementioned date ranges," Ookla said.The ad regulator also questioned the test methodology of Ookla."While the advertiser submitted an Ookla certificate, they did not provide an explicit test methodology to substantiate that the method is robust to capture that the sample; and is representative and comparable across operators, geographies and consumers," ASCI observed.The ASCI committee referred to the TRAI website with respect to the coverage of Airtel vis-a-vis Reliance Jio and noticed that there is a significant gap between geographical dispersion of Airtel and Jio 4G subscribers which could impact the comparison."Based on this data, the FTCC concluded that the claim was not adequately substantiated and the basis of comparison has been so chosen as to bestow artificial advantage to the advertiser," it said.ASCI said that "the claim by the advertiser is not specific to 4G technology whereas the TVC has visuals with reference to 4G. The speed comparison visual also has a reference to 4G in the notification bar and shows poor signal strength for the other service provider.""The FTCC considered this representation to be misleading by ambiguity and implication," it added.ASCI has granted a personal hearing to Reliance JioInfocom and Bharti Airtel's representatives with the technical expert.