4-26
Configuring E1 and T1 Interfaces
ProCurve Secure Router Modules
same polarity without an intervening pulse of the opposite polarity. An EXZ
is the occurrence of any zero string length equal to or greater than three for
B3ZS or greater than four for HDB3. LCVs usually signal a mismatch in line
coding type. For example, the local interface uses AIM, but the remote
endpoint uses HDB3.
LES. A Line Errored Second (LES) occurs if one or more of the following are
detected in a one-second time interval:
■ LCVs (that is, one or more BPVs or EXZs)
■ LOS
The LES count lists the number that have occurred.
PCV. A PCV is caused by a frame synchronization bit error in a D4 or E1 frame.
If a T1-carrier line uses ESF or if an E1-carrier line uses CRC4, a PCV is an
error detected by the CRC.
SEFS. The number of seconds during which an OOF or LOS occurred.
SES. For a T1-carrier line using ESF, a Severely Errored Second (SES) is one-
second time interval during which one of the following occurs:
■ 320 or more PCVs
■ one or more OOF defects
■ an AIS
For an E1-carrier line using CRC4, an SES occurs in one of the following is
detected during a one-second interval:
■ 832 or more PCVs
■ one or more OOF defects
For a T1-carrier line using D4 frame formatting, an SES is a second with at
least one framing error, OOF defect, or 1544 or more LCVs.
For an E1-carrier line, an SES is caused by 2048 or more LCVs in a second.
UAS. Unavailable Seconds (UAS) are calculated by counting the number of
seconds that the interface is unavailable. An E1 or T1 interface becomes
unavailable after ten contiguous SESs or the onset of the condition that led to
the failure. If the condition leading to the failure was immediately preceded
by one or more contiguous SESs, then the UAS are counted from the onset of
these SESs.
To Next Page
Loading...
Need help?
General
