Download Troubleshooting

TROUBLESHOOTING
BEN FINEMAN,
PROGRAM MANAGER, NET+ VIDEO, VOICE AND COLLABORATION SERVICES
INTERNET2
JUSTIN TRIEGER,
DIRECTOR OF NEW MEDIA AND DISTANCE LEARNING
NEW W ORLD SYMPHONY
NETWORK TROUBLESHOOTING
Justin Trieger | Technical Director for
Distance Education
www.nws.edu
Identifying The Problem
Do you see it?
Packet Loss, Computer Resources,
Format Conflict
Can you hear it?
Packet Loss, Jitter, Distortion
Do you feel it?
Jitter, Latency, Audio/Video Issues
Common Video Issues
Format Mismatch – ensure the format generated by the camera is the
format the encoding device is expecting. (i.e. HD-SDI -> HD-SDI
Out-Of-Sync – clock of encoding device is at odds with the camera
signal.
Common Audio Issues
Improper Gain Stage – distortion or high level of noise due to structure
of amplification in signal.
Buffer Saturation – hardware or software buffer is too small to handle
data flow.
Sampling Rate – mismatch in sampling rate from the source can result in
audio anomalies.
Network Troubleshooting
START AT THE BEGINNING!
Confirm network traffic is taking the path it should.
R&E Network
Commodity
Internet
START AT THE BEGINNING!
Symmetry is not only beautiful,
it makes for clean transmissions
R&E Network
Commodity
Internet
R&E Network
LOCAL HOST
• Is the device operating with CPU/RAM headroom?
• Is the network connection and configuration correct?
• Are video and audio signals ingested without issue?
• If a loopback test can be performed (127.0.0.1), is the signal
received without error?
THE LAN
Step One: Establish a clean connection host to host
THE LAN
Step Two: Incrementally move through the network
topology switch by switch
Switch One
Host A
(Host B)
THE LAN
Step Two: Incrementally move through the network
topology switch by switch
Switch One
Switch Two
Host A
Host B
THE LAN
Step Two: Incrementally move through the network
topology switch by switch
Switch One
Switch Two
Host A
Switch Three
(Host B)
THE LAN
Step Two: Incrementally move through the network
topology switch by switch
Switch One
Host A
(Host B)
Switch Two
Router
Switch Three
THE LAN
Step Two: Incrementally move through the network
topology switch by switch
Switch One
Host A
Switch Two
(Host B)
Router
Switch Three
(Host B)
(Host B)
NOW WHAT?!
• Make sure the far-end does the same LAN testing
• Compile all your findings including traceroutes, throughput testing,
application errors etc. and send this to your respective R&E network
providers
• Perhaps even better, invite them for a happy hour beer first
www.nws.edu
PERFSONAR
perfSONAR is a network measurement toolkit designed to provide federated
coverage of paths, and help to establish end-to-end usage expectations.
• Runs on a light version of Linux
• Is configured to run regular tests against other perfSONAR
nodes to verify network connectivity
• Uses accuracy instead of load testing to verify network links
NUTTCP
Nuttcp is a cross-platform (Unix, Solaris, BSD, Windows) network diagnostic
tool used to measure raw TCP and UDP throughput at the network layer.
IPERF
iPerf is tool for active measurements of the maximum achievable bandwidth
on IP networks. It supports tuning of various parameters related to timing,
buffers and protocols (TCP, UDP, SCTP with IPv4 and IPv6). For each test it
reports the bandwidth, loss, and other parameters.
Questions?