403. That’s an error.
Your client does not have permission to get URL /videoplayback?id=b2a0457650691527&itag=18&source=webdrive&requiressl=yes&ttl=transient&mm=30&mn=sn-ab5l6n7y&ms=nxu&mv=u&pl=48&ei=yZ40WczAJInoqAXK1JSoCw&driveid=0B312Q7i7vYpcSVRmU0dGUmRTN1E&mime=video/mp4&lmt=1496549893352768&mt=1496620330&ip=2604:a880:0:1010::1b81:f001&ipbits=0&expire=1496635145&sparams=ip,ipbits,expire,id,itag,source,requiressl,ttl,mm,mn,ms,mv,pl,ei,driveid,mime,lmt&signature=AE9A18FED9EDE5D8AF9418EFFD67C4D14111A1B9.79A72B1C99EC73162750E7057F689597A3A2E9D9&key=ck2&app=explorer&jparams=MjQuODUuMTMuMTg1&upx=TW96aWxsYS81LjAgKFdpbmRvd3MgTlQgMTAuMDsgV2luNjQ7IHg2NCkgQXBwbGVXZWJLaXQvNTM3LjM2IChLSFRNTCwgbGlrZSBHZWNrbykgQ2hyb21lLzU4LjAuMzAyOS4xMTAgU2FmYXJpLzUzNy4zNg&tr=2
from this server. That’s all we know.