Cisco Systems 7304 manual Configuring Scramble, Verifying MDL, 13-10

Chapter 13 Configuring the 2-Port and 4-Port T3/E3 SPAs

Configuration Tasks

Verifying MDL

Use the show controllers serial command to display the MDL settings:

router# show controllers serial 6/0/0 Serial6/0/0 -

Framing is c-bit, Clock Source is Line

Bandwidth limit is 44210, DSU mode 0, Cable length is 10 rx FEBE since last clear counter 2, since reset 0

Data in current interval (546 seconds elapsed):

0 Line Code Violations, 0 P-bit Coding Violation 0 C-bit Coding Violation

0 P-bit Err Secs, 0 P-bit Sev Err Secs

0 Sev Err Framing Secs, 0 Unavailable Secs

0 Line Errored Secs, 0 C-bit Errored Secs, 0 C-bit Sev Err Secs Data in Interval 1:

0 Line Code Violations, 0 P-bit Coding Violation 0 C-bit Coding Violation

0 P-bit Err Secs, 0 P-bit Sev Err Secs

0 Sev Err Framing Secs, 0 Unavailable Secs

0 Line Errored Secs, 0 C-bit Errored Secs, 0 C-bit Sev Err Secs

.

.

.

Data in Interval 96:

0 Line Code Violations, 0 P-bit Coding Violation 0 C-bit Coding Violation

0 P-bit Err Secs, 0 P-bit Sev Err Secs

0 Sev Err Framing Secs, 0 Unavailable Secs

0 Line Errored Secs, 0 C-bit Errored Secs, 0 C-bit Sev Err Secs Total Data (last 24 hours)

0 Line Code Violations, 0 P-bit Coding Violation, 0 C-bit Coding Violation,

0 P-bit Err Secs, 0 P-bit Sev Err Secs,

0 Sev Err Framing Secs, 0 Unavailable Secs,

0 Line Errored Secs, 0 C-bit Errored Secs, 0 C-bit Sev Err Secs

No alarms detected.

0 Sev Err Line Secs, 1 Far-End Err Secs, 0 Far-End Sev Err Secs 0 P-bit Unavailable Secs, 0 CP-bit Unavailable Secs

0 CP-bit Far-end Unavailable Secs

0 Near-end path failures, 0 Far-end path failures

No FEAC code is being received

MDL transmission is enabled

EIC: tst, LIC: 67,

Test Signal GEN_NO: test

Far-End MDL Information Received

EIC: tst, LIC: 67,

Test Signal GEN_NO: test

Configuring Scramble

T3/E3 scrambling is used to assist clock recovery on the receiving end. Scrambling is designed to randomize the pattern of 1s and 0s carried in the physical layer frame. Randomizing the digital bits can prevent continuous, nonvariable bit patterns—in other words, long strings of all 1s or all 0s. Several physical layer protocols rely on transitions between 1s and 0s to maintain clocking.

	Cisco 7304 Router Modular Services Card and Shared Port Adapter Software Configuration Guide
13-10	OL-4807-02