Verilink PRISM 3060-10 (34-00252.4) Product Manual - Manual (Page 36)

28 O PERATION
T1 Network
Loop
The unit monitors network loopback commands and activates loops based upon
their reception as described in TR 54016 and T1.403. Refer to Figure 3-14 for a
depiction of the loop modes (See also Figure 4-7 and Network LLB on page 47).
Figure 3-15 shows an example of a T1 Network screen. The Diagnostics menu
allows for loopback and BERT functions as explained in the following paragraphs.
The looping choices are as follows (note that loops cannot be put up or taken
down during a test, but can be established before running a BERT).
NONE
Network loop not present.
LOOP FAR
Sends loop codes over the network to the far-end unit to force it into a NET LLB.
UNLOOP FAR
Sends unloop codes to the far-end unit to remove the loop condition.
NET PLB
The payload loopback selection loops the data back toward the network. Framing,
CRC, and FDL are regenerated and all ones are passed to the DTE ports.
NET LLB
The local loopback selection loops data received from the network back toward the
network. Received data is also passed through to the DTE ports as normal.
DTE MLB
The T1 DTE maintenance loopback loops network data back toward the DTE at
the network interface. Data is also passed through to the network.
Port
Loops
Ports are indicated as Slot 3 through 6 and DSU 1 through 6. The looping choices
are only available for DSU MP cards that are installed and configured. Only the
appropriate loops (shown under Type) for a card’s configuration are selectable.
Loops are shown on the DSU MP side of Figure 3-14 and labeled in Table 3-3.
BERT
Functions
The following menus offer selections for the BERT pattern, type, and results.
BERT Pattern
This field is used to specify which pattern is transmitted toward the port being
tested. The choices are QRSS, 63, 511, 2047, 2
15
-1, 2
20
-1, and 2
23
-1, 1:8, 3:24,
ALT, and CLEAR. 511 is the only choice for the DSU MP.
Diagnostics
T1 Network Loop ---- Loop Far <
igure 3-15 Diagnostics Screen