This paper presents a new 3D video database (STESCAL3D -Stereoscopic Scalable 3D), made up of 3D stereo video sequences affected by different types of degradations. A set of subjective quality grades have been collected in three geographically displaced sites. The database contents have been produced using scalable video coding to encode 3D stereo video clips with distinct encoding parameters, after which different transmission degradations have been applied to the encoded video streams. These sequences have been subjectively evaluated by observers from three countries, Croatia, Portugal and Greece, using a purpose-built web-based platform. The subjective quality data compiled were processed, analyzed and compared to quality estimates obtained using several well-known objective measures. It is shown that the correlation between objective quality estimates and the subjective quality grades is in general low. Additionally the results show that stereo-view asymmetries in terms of encoding parameters and packet loss ratio (PLR) leads to low quality of experience. The video database and the subjective grades collection are publicly available with the referral link provided in the text.