Chapter 10: Troubleshooting
▪
snmpset -v 1 -c public <ip-address-of-unit> .1.3.6.1.2.1.10.30.5.1.9.6 i 1
(terminates loopback as in dsx3NoLoop(1))
▪
snmpget -v 1 -c public <ip-address-of-unit> .1.3.6.1.2.1.10.30.5.1.9.6
(returns current loopback value of DS3 Port 2)
•
SNMP FEAC Initiation
: See above for VACM MIB write-access description first. An SNMP
request can set the local converter's dsx3SendCode variable to dsx3SendLineCode, which
requests the remote converter to loopback DS3 data received. The following sample SNMP
command could instruct a converter configured in C-Bit DS3 framing mode to send FEAC
loopback commands to a remote converter:
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snmpset -v 1 -c public <ip-address-of-unit> .1.3.6.1.2.1.10.30.5.1.7.6 i 2
(.6 is DS3 Port 2; .5 would be DS3 Port 1; dsx3SendLineCode(2) initiates FEAC loop cmd)
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snmpset -v 1 -c public <ip-address-of-unit> .1.3.6.1.2.1.10.30.5.1.7.6 i 4
(sends FEAC disable loopback as in dsx3SendResetCode(4) NOT dsx3SendNoCode(1))
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snmpset -v 1 -c public <ip-address-of-unit> .1.3.6.1.2.1.10.30.5.1.7.6 i 1
(Does nothing! Dsx3SendNoCode(1) will not terminate a loopback set up with a FEAC
loopback request, just stop sending a request to begin one. Use dsx3SendResetCode(4))
▪
snmpget -v 1 -c public <ip-address-of-unit> .1.3.6.1.2.1.10.30.5.1.7.6
(returns current value for DS3 Port 2)
•
Upon successful loopback initiation, the web management status screen of the converter will
also indicate that a DS3 line is in loopback and testing administrative mode.
•
VACM Settings for SNMP DS3 MIB access
: The SNMP area of the web management
configuration screen of the converter allows an operator to grant write-access to specific
SNMP MIB variables. Press “Login to view sensitive SNMP community/security
information” then add the following line exactly (or a more secure one):
authcommunity read,write public default .1.3.6.1.2.1.10.30.5.1
to the “Access Rights – snmpd.conf ” section, submit changes, and confirm error-free in the
“Status – snmpd.conf ” section. Remember to remove this line when done testing to maintain
a completely secure system. This enables the configuration and loopback sections of the DS3
MIB using community name public for all IP hosts.
Performance
Performance issues are addressed in the previous chapter.
Interoperability
The interoperability section of this manual should be reviewed to ensure that appropriate equipment is
connected to the converter. Connected LAN equipment should adhere to 802.3 standards, and connected
telecom equipment should be in unchannelized mode, i.e., not broken into T1 or E1 channels.
Laboratory Testing
The converters may be tested back-to-back before introducing a complicated E3 or T3/DS3 link. To do so,
the E3, T3/DS3 output port from one converter should be connected to the input port on the second through
an appropriate 75-ohm cable. The input port on the first converter should be connected to the output port of
the second in a similar manner.
Pinging
Ping is not reliable
. The protocol which ping programs use does not guarantee delivery of the data
packets.
Ping programs from major software and hardware corporations are known to contain bugs,
both in packet content and function
. Generally, however, nearly all of the ping packets on a test network
that is not over-loaded should get through; if fewer are received, there is probably a problem.
The ping program is a useful, simple test for a TCP/IP Ethernet network. It is a program that sends a data
packet from a source machine to a destination machine, which then returns a response packet. There is a
plethora of information about ping and the free public-domain ping utilities available. Ping is often
supplied as a standard operating system utility, and often the command “ping” followed by the destination
machine's IP address or hostname is all that is required to be typed at the source machine's command line.
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