|
|
| (15 intermediate revisions by the same user not shown) |
| Line 1: |
Line 1: |
| − | = Voice only analysis =
| + | * [[Traffic measurements Audio]] |
| − | | + | * [[Traffic measurements Video]] |
| − | The following screenshot shows network-traffic (in Bytes/s) for the following connections:
| |
| − | | |
| − | * '''Black''': traffic from and to Trixbox #1
| |
| − | * '''Red''': traffic between the 2 Windows machines running X-lite
| |
| − | * '''Green''': traffic between laptop #1 and its Asterisk
| |
| − | * '''Blue''': traffic between the two Asterisk PBX's | |
| − | * '''Pink''': traffic between Windows machine #1 and its Asterisk
| |
| − | | |
| − | [[Image:ethereal_graph_voice-only.png]] | |
| − | | |
| − | From the graph shown above there can be concluded that indeed the two X-Lite machines are only connected to their own Trixbox, i.e. there is no ''direct'' traffic between the two X-Lite machines.
| |
| − | | |
| − | = Voice and video analysis =
| |
| − | | |
| − | Schematic sketch of the situation:
| |
| − | | |
| − | [[image:Schematic overview asterisks and sip-phones.gif]] | |
| − | | |
| − | In the screenshot below, the following events were measured:
| |
| − | * @4 sec: Video was turned on
| |
| − | * @14 sec: Video was set to black (connection lost with DVdriver)
| |
| − | * @20 sec: Video showed moving pictures again.
| |
| − | | |
| − | [[Image:ethereal_graph_voice_and_one-way-video.png]]
| |
| − | | |
| − | Legenda:
| |
| − | * '''Black''': traffic from and to Trixbox #1
| |
| − | * '''Red''': traffic between the 2 Windows machines running X-lite
| |
| − | * '''Green''': traffic between laptop #1 and its Asterisk
| |
| − | * '''Blue''': traffic between the two Asterisk PBX's
| |
| − | * '''Pink''': traffic between Windows machine #1 and its Asterisk
| |
| − | | |
| − | The following graph shows the traffic is almost constant.
| |
| − | Till 35sec the conversation included audio and video. The rest is audio-only.
| |
| − | | |
| − | [[Image:ethereal_graph_voice_and_one-way-video2.png]]
| |
| − | | |
| − | This measurement shows there is no traffic between both SIP-phones, only via (both) Asterisk PBX.
| |
| − | | |
| − | = Differences between voice and video =
| |
| − | For this test, we connected 2 SIP phones to the same Asterisk PBX.
| |
| − | We meassured the bandwitdh used between the following 3 points:
| |
| − | | |
| − | # SIP-phone #1 with camera
| |
| − | # SIP-phone #2 without camera
| |
| − | # Asterisk PBX
| |
| − | | |
| − | [[image:ethereal_graph_difference_voice and video.png]]
| |
| − | | |
| − | Legenda:
| |
| − | * Black shows audio & video from SIP-phone #1 to the PBX (video starting at the 10<sup>th</sup> second)
| |
| − | * Blue shows audio-only from SIP-phone #2 to the PBX
| |
| − | * Pink shows all traffic between SIP-phone #1 and the PBX (both directions)
| |
| − | | |
| − | The debug-screen [[image:X-lite debug-info.png|right|157px]] of X-lite (Ctrl + F9) told us the SIP-phone assumed a total available bandwith of 256/256 kbps.
| |
| − | This was filled with 64 kbps for speech (protocol g711u) and 131 kbps for video (protocol H263-1998)
| |
| − | | |
| − | When looking at the speech traffic:
| |
| − | * 50 packets/sec (meassured with Ethereal)
| |
| − | * 214 Bytes/packet (meassured with Ethereal)
| |
| − | * +/- 10,7 kByte/s
| |
| − | * 160 bytes audio-data per packet (64 kbps = 8000 Bytes/sec, 50 packets/sec)
| |
| − | * UDP-packet-header: 28 Bytes.
| |
| − | | |
| − | Meassured IAX-overhead: (the g711u codec uses a CBR of 64kbps) 214 - 28 - 160 = 26 Bytes/packet.
| |
| − | Thus 1300 Bytes/sec IAX overhead. (10k4 bps)
| |
