• H.245 OLC & OLC ACK
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• H.460.18 (Signaling) • H.460.19 (Media)
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云视频
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• Captures which do not include call signaling will list RTP as UDP packets; H.245 as TCP packets only.
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• 分析RTP Stream
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• 分析TCP Stream
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10Βιβλιοθήκη 云视频© Polycom, Inc. All rights reserved.
How to capture? Wireshark的安装 Wireshark的使用 How to read H.323 message? 网络设备对我们的影响 断线问题案例 ALG故障案例
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• Important things first: Wireshark will not usually recognize any VoIP calls in a capture unless call signaling (H.225.0, H.245, SIP/SDP) is also included inthe capture.
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• 交换机镜像(Mirror + Wireshark) • 设备本身抓包(下载后，使用Wireshark进行分析） • RPAD抓包的方法 • DMA抓包的方法
• RPD抓包的方法 • RMX抓包的方法
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3
云视频
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云视频
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• H.225 Admission
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• H.225 Connect
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How to capture? Wireshark的安装 Wireshark的使用 How to read H.323 message? 网络设备对我们的影响 断线问题案例 ALG故障案例
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• 注意以下界面，一定要安装WINCAP。
© Polycom, Inc. All rights reserved.
How to capture? Wireshark的安装 Wireshark的使用 How to read H.323 message? 网络设备对我们的影响 断线问题案例 ALG故障案例
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• TCP layer issue • UDP layer issue • ALG
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• TCP三次握手 • 发起断链
• 发起断链
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• HDX systems transmit H.245 RoundTripDelayRequest every 30 seconds. • An H.323 system is not required to transmit H.245 RoundTripDelayRequest • It is mandatory that a system which received H.245 • RoundTripDelayRequest acknowledge the request with H.245 RoundTripDelayResponse • If HDX does not receive RoundTripDelayResponse, it will terminate the H.323 call
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①Wireshark considers all out-of-order packets as being lost. ②Wireshark will NOT consider late-arriving packets as being lost if the packets are still captured in order, nomatter how late those packets arrive. ③Jitter calculations done by Wireshark should be ignored.
Carol.Zhao@
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云视频
© Polycom, Inc. All rights reserved.
How to capture? Wireshark的安装 Wireshark的使用 How to read H.323 message? 网络设备对我们的影响 断线问题案例 ALG故障案例
5
云视频
© Polycom, Inc. All rights reserved.
How to capture? Wireshark的安装 Wireshark的使用 How to read H.323 message? 网络设备对我们的影响 断线问题案例 ALG故障案例
6
• Filter
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