The goal of this report series is to equip telecom industry decision-makers with a comprehensive view of spending trends and vendor market power in their industry. To do this we assess technology vendors' revenues in the telecom vertical, across a wide range of company types and technology segments. We call this market "telco network infrastructure", or "Telco NI." This study tracks 137 Telco NI vendors, providing revenue and market share estimates for the 1Q13-2Q25 period (i.e. 50 quarters). Of these 137 vendors, 111 are actively selling to telcos; most others have been acquired by other companies in the database. For instance, ADVA is now part of Adtran, but both companies remain in the database because of historic sales.