T1 test patterns

[jrsmithy]

While troubleshooting a T1 issue recently, I came across a TechDoc that recommended using 4 data patterns in an extended ping to test the circuit. The patterns are: 0x0000, 0x1111, 0xaaaa and 0xffff. I know the 0x0000 and 0xffff equate to a Service Provider test pattern of all zeros and all ones, but what Service Provider test patterns do the other 2 equate to? Also, what does the default of 0xabcd equate to?

[Richard Burts]

James

the 0x1111 produces a pattern of 0001000100010001 (alternating 0 and 1 with majority of 0s), the 0xaaaa produces 1010101010101010 (equal distribution of 0 and 1 alternating), and the default of 0xabcd produces 1010101111001101 (alternating 0 and 1 with majority of 1s).

HTH

Rick

[pciaccio]

The pattern of all 1's (oxfffff) tests out the power of the equipment. This will stress the power circuitry within the equipment as well as the T-1 circuitry. A pattern of all 0's tests the clocking ability of the T-1 and equipment. If you have a floating clock or drifting clock, this pattern will weed out culprit. The pattern of 0xaaaa is alternating zeros and ones. This tests the over all circuitry to see if it can alternate bits continously.The pattern of 0x1111 will throw a one bit after every 8 bits. This tests out the B8ZS ability of the T-1. If you have a mismatch of B8ZS and AMI on a line, this pattern should show you errors. All these patterns can be tested using a BERT test set directly on the T-1 line, but the PING can perform these tests as well by shaping the data to your needs...Hope this helps..

[vijayasankar]

Hi Phil,

Thanks for the info.

-VJ