Review: Paessler PRTG Traffic Grapher 5.3

Paessler's bandwidth and protocol monitor can help firms keep key apps healthy

Launched in April, version 5.3 of Paessler’s PRTG Traffic Grapher is an easy-to-use bandwidth and network protocol monitor that can monitor personal network connections or the main wide area network (WAN) connection coming into an organisation.

The main new feature in this release is support for versions 2c and 3 of the Simple Network Management Protocol (SNMP). SNMP 2c is basically version 2 of SNMP without the security model introduced in version 2, and SNMP 3 is recognised by the Internet Engineering Task Force (IETF).

One of the three monitoring options is through the SNMP-enabled devices found through PRTG’s automatic network discovery. One advantage of using SNMP is that other parameters, such as disk usage and hardware temperatures, can be monitored.

The other two options are to packet-sniff traffic using the local system’s network cards; or, for high-traffic networks, to use the Netflow protocol employed by most Cisco routers. The easiest approach is to set up packet-sniffing mode; we added a “sensor” by just selecting the Ethernet port on our laptop, which PRTG detected.

PRTG’s primary screen is divided into three sections, the main one showing various graphs of the currently selected sensor’s data transfer rate (in kbit/s) against time.

From top to bottom on the screen, the graphs show data transfer rates for the last 60 minutes, 24 hours, 30 days and 365 days data, and these values can be user-defined.

PRTG can plot data transfer rates from many different protocols, including DNS, FTP, HTTP, HTTPS, ICMP, Imap, IRC, Netbios, POP3, RDP, SMTP, SNMP, and Telnet.

The left section gives options to choose which sensor graphs are displayed, including remote access to web servers of other systems running PRTG; and lets users create reports and choose who to send them to. The middle section lets users choose which Ethernet ports on switches or routers discovered via SNMP will be used as sensors.

For example, we could use SNMP mode to set up all the 10/100Mbit/s Ethernet ports of our 3Com SuperStack 4250T switch as sensors and set up one of the gigabit uplinks to our broadband ADSL2+ connection as the main WAN sensor. Using PRTG we measured the maximum downlink speed for the connection as exactly 16Mbit/s.

PRTG could be used by firms to charge departments for bandwidth usage, or by ISPs to charge their customers. We could set up billing with a base fee and then add percentage-based or volume-based charges. We could also access PRTG through its in-built web server. This could allow authorised staff or groups to access PRTG over a LAN or the internet.

Paessler also produces SNMP helper software, which allows other systems running Traffic Grapher to monitor running servers.

To trial the software, firms can download a free version limited to three “sensors” or download a complete version for 30 days use. PRTG is priced per sensor or port, starting at £34 + VAT to monitor 25 ports.