T1 Lines and Cable Internet services are both designed to offer high speed connections, but the T1 line offers synchronous (same upload and download bandwidth) speeds while Cable is ansynchronous (different upload and download bandwidth - normally large download bandwidth and small upload bandwidth making it extremely unreliable for serving content). T1 Lines also offer a higher level of service quality, up time, faster repair times and fewer end user restrictions. Cable is normally a "best possible" offering, meaning there are few or no service guarantees. Cable providers also tend to over subscribe their lines, leading to increased network congestion during peak usage periods. A full T1 line has guaranteed bandwidth.