Black Box LRU4240 - Manual (Page 84)

72 SALES: 0870 90 10 750 Dual Trunk E1 Router User’s Guide
Dual Trunk E1 Router
Link-based Testing for Public Packet Networks
The link-based testing feature qualifies and tests PPP-based networks non-intrusively. Using the
ICMP ping packet, the unit adds pattern generation and packet sequencing that allows single-ended
and collaborative testing. This lets the user test his network from one end to the other using any
TCP/IP-based test equipment. Link-based testing encapsulates a BERT pattern inside an ICMP
message that the remote Dual Trunk E1 Router reflects. The packet can then be directed to test the
network, or LAN port. Patterns supported include 511, 1023, 2047, all 1s, all 0s, and alternating 1s
and 0s.
Delay Monitoring for TCP/IP
The delay monitoring feature provides network delay measurement beyond the link between the
Dual Trunk E1 Router and any IP-addressable device on the network. Blackbox measures delay by
using ping packets, which timestamp and obtain round-trip delays to specific IP addresses. The
traffic added to support the measurement is minimal, and the user can configure the frequency. The
length of the ping packet can allow delay measurements at different frame sizes. A user who is
concerned about bandwidth taken away by the measurement can configure the test for a single, short
ping every few minutes, making the test bandwidth penalty virtually non-existent.
The link-based testing and delay monitoring features allow network managers to test links and
quantify delays, and are especially useful during network installation and trouble isolation. Both
features provide the benefit of circuit-level testing across the network.
Non-Disruptive Testing
The Link Layer Diagnostics and Delay Monitoring are non-disruptive to normal traffic. Unlike hard
loopback tests that affect the line, Link Layer Diagnostics do not take the line out of service.
Depending on the link speed and the test specified, Link Layer Diagnostics uses some of the
bandwidth that would otherwise be available for payload. This bandwidth reduction is negligible if
the test is specified with short and infrequent packets.
On point-to-point networks Link Layer Diagnostics do not disrupt payload traffic.
Menu-9B—Link Layer Diagnostics
Link Layer Diagnostics uses an encapsulated Bit Error Rate Test (BERT) pattern inside ping
messages and reflects the BERT pattern from the remote unit.
1. Select a pattern test.
2. Select the IP address of the equipment to send the PING message.
Select the local or remote router, or the remote Dual Trunk E1 Router.
3. Select a port to test.
Ports are NET, Ethernet, and COM.
4. Select the Test Interval
Select time in seconds between 2 ping messages.