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Generic troubleshooting processes: Difference between revisions
Generic troubleshooting processes (view source)
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So for instance change the viewable timeframe from 1 minute to “1 day LIVE” or “Last day”, to get a clear overview of the TOP talkers over a 1 day timeframe. | So for instance change the viewable timeframe from 1 minute to “1 day LIVE” or “Last day”, to get a clear overview of the TOP talkers over a 1 day timeframe. | ||
For identical time frames, let’s say “10 minutes LIVE” and “Last 10 minutes”, both view modes will display exactly the same graphs. Only in table form, the practical difference between the two becomes evident. | For identical time frames, let’s say “10 minutes LIVE” and “Last 10 minutes”, both view modes will display exactly the same graphs. Only in table form, the practical difference between the two becomes evident. | ||
[[File:Top talker 2.png|1000x1000px|alt=]] | [[File:Top talker 2.png|1000x1000px|alt=]] | ||
As becomes clear from the above illustration, LIVE-view will display TOP Talker information -for the selected LIVE timeframe- (in our case 10 minutes) accompanied with live traffic indicators based on packets per second and bits per second. When selecting the “Last 10 minutes” view mode, the TOP talkers will be accompanied by total traffic in packets and Bytes – during the selected time frame. This can be of great help to more quickly and easily identify communication relations. | As becomes clear from the above illustration, LIVE-view will display TOP Talker information -for the selected LIVE timeframe- (in our case 10 minutes) accompanied with live traffic indicators based on packets per second and bits per second. When selecting the “Last 10 minutes” view mode, the TOP talkers will be accompanied by total traffic in packets and Bytes – during the selected time frame. This can be of great help to more quickly and easily identify communication relations. | ||
The download buttons, that you find everywhere throughout the Allegro web interface, give you quick and easy access to pre-filtered Pcap files. | The download buttons, that you find everywhere throughout the Allegro web interface, give you quick and easy access to pre-filtered Pcap files. | ||
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If you want very detailed information about a certain IP, go to the IP-details page of that specific IP. This is easily done, by clicking on an IP, everywhere throughout the Allegro web interface. This will bring you to the IP-details page of that specific IP-address. The IP-details page, gives you 1-click access to all sorts of network performance information -during the selected time frame-. The different tabs that you can go through on the IP-details page, are highlighted in green in the image below. | If you want very detailed information about a certain IP, go to the IP-details page of that specific IP. This is easily done, by clicking on an IP, everywhere throughout the Allegro web interface. This will bring you to the IP-details page of that specific IP-address. The IP-details page, gives you 1-click access to all sorts of network performance information -during the selected time frame-. The different tabs that you can go through on the IP-details page, are highlighted in green in the image below. | ||
[[File:IP details TABS.png|1200x1200px]] | [[File:IP details TABS.png|1200x1200px]] | ||
Click on the image below for an enlarged view of a full IP details page. | Click on the image below for an enlarged view of a full IP details page. | ||
[[File:IP details.png|none|thumb|495x495px]] | [[File:IP details.png|none|thumb|495x495px]] | ||
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=== <u>Burst Analysis</u> === | === <u>Burst Analysis</u> === | ||
The first graph on Allegro’s predefined quality dashboard, represents “Burst Analysis”. Because the Allegro Network Multimeter supports data measurement intervals (sampling rates), as detailed as 1 ms, you can identify instances where a Link is 100% saturated, for very short fractions of time. Evidently, micro bursts could potentially be a root cause for network performance issues. Other than Allegro Packets, most monitoring & troubleshooting solutions are unable to pick this up, because of “low resolution” data sampling (i.e. 1, 5, or even 10 minutes). | The first graph on Allegro’s predefined quality dashboard, represents “Burst Analysis”. Because the Allegro Network Multimeter supports data measurement intervals (sampling rates), as detailed as 1 ms, you can identify instances where a Link is 100% saturated, for very short fractions of time. Evidently, micro bursts could potentially be a root cause for network performance issues. Other than Allegro Packets, most monitoring & troubleshooting solutions are unable to pick this up, because of “low resolution” data sampling (i.e. 1, 5, or even 10 minutes). | ||
=== <u>Response times</u> === | === <u>Response times</u> === | ||
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From here, it is very easy to identify -and zoom in on- timing related issues that happened on the network. In the 1-day time frame exampled above, clearly HTTP and DHCP show instances where response time deviated massively from the overall median line. | From here, it is very easy to identify -and zoom in on- timing related issues that happened on the network. In the 1-day time frame exampled above, clearly HTTP and DHCP show instances where response time deviated massively from the overall median line. | ||
You can select such a spike in the graph by clicking and holding the left mouse-button, selecting the spike and then releasing the left mouse-button. When zoomed in to your liking, click on the graphs title (e.g. DHCP) which will bring you to that specific details page. | You can select such a spike in the graph by clicking and holding the left mouse-button, selecting the spike and then releasing the left mouse-button. When zoomed in to your liking, click on the graphs title (e.g. DHCP) which will bring you to that specific details page. | ||
[[File:DHCP.png|1100x1100px]] | |||
Because you already zoomed into to a specific time frame on the graph, this page will now only show you the client / DHCP-server relations, that happened during the time frame that you selected in the graph. Also on this page, you’ll find a download button for simple (retroactive) extraction of a Pcap, that is pre-filtered to only contain DHCP and BOOTP packets. | Because you already zoomed into to a specific time frame on the graph, this page will now only show you the client / DHCP-server relations, that happened during the time frame that you selected in the graph. Also on this page, you’ll find a download button for simple (retroactive) extraction of a Pcap, that is pre-filtered to only contain DHCP and BOOTP packets. | ||
=== <u>UDP Jitter & packet loss</u> === | === <u>UDP Jitter & packet loss</u> === | ||
The next two graphs provide trending and actionable insights for UDP-based protocols RTP and Profinet. First up is the graph depicting Jitter over time. Bad jitter can have a very negative impact on business critical production services and on VoIP- / Unified Communication services. | The next two graphs provide trending and actionable insights for UDP-based protocols RTP and Profinet. First up is the graph depicting Jitter over time. Bad jitter can have a very negative impact on business critical production services and on VoIP- / Unified Communication services. | ||
[[File:Jitter.png|700x700px]] | |||
From this graphs, it is very easy to quickly identify quality issues, such as instances where jitter is above 20ms in networks where VoIP is being used. | From this graphs, it is very easy to quickly identify quality issues, such as instances where jitter is above 20ms in networks where VoIP is being used. | ||
=== <u>TCP retransmissions/packet loss</u> === | === <u>TCP retransmissions/packet loss</u> === | ||
The next two graphs provide trending visibility and information about TCP packet loss in your network. TCP retransmission are seen in all networks, it’s the amount of retransmission -and better yet the retransmission ratio in percent- that indicate if things are problematic in your network. This is why graphs for both TCP retransmissions in absolute numbers, as well as in ratio are presented to you. | The next two graphs provide trending visibility and information about TCP packet loss in your network. TCP retransmission are seen in all networks, it’s the amount of retransmission -and better yet the retransmission ratio in percent- that indicate if things are problematic in your network. This is why graphs for both TCP retransmissions in absolute numbers, as well as in ratio are presented to you. | ||
[[File:Tcp.png|700x700px]] | |||
As a reference; for wired infrastructures, a retransmission ratio of up to 2% is generally accepted to still be okay. In wireless infrastructures however, retransmissions of up to 10% are very common and considered to be a well-functioning wireless network. | As a reference; for wired infrastructures, a retransmission ratio of up to 2% is generally accepted to still be okay. In wireless infrastructures however, retransmissions of up to 10% are very common and considered to be a well-functioning wireless network. | ||