Your question is interesting but a little ambiguous:

• Do you want to verify the size of a circuit that you use alone?
• Or, is the T1 shared with others?
• Do you want to see if you get T1 throughput across the ISP to the backbone (differnet question)?
• Do you want to see if congestion is such that you actuall get T1 speeds and where?

Remember that you are using IP.... .and TCP/IP tools can only verify TCP/IP related parameters..... a T1 congested with loads of IP traffic can perform like a 28 KB modem, right? So, TCP/IP tools have only limited value when discussing circuits and other wire-speed parameters.

The broader anwer to you question is that MANY people pay for T1 ISP connections but for many reasons cannot get the benefits of T1 because of:

• How their ISP is configured?
• How circuits and router ports are shared.
• The underlying transport of the T1 (frame relay, ATM, etc.)
• Poor ISP connections to the big I backbone.
• Oversold pipes and ports by ISP (congestion problems).
• Firewalls and proxy services slowing down the link.
• etc. etc. etc.

As you might guess, it is necessary to be very configuration and topologically specific when discussing network performance issues......