Archives: VoIP

sip monitoring tools No ratings yet.

Some good monitoring tools: homer: easy to install with docker for its server and install helifpy on a  sip/client/host : nohup ./heplify -hs homer_server:9060 & grep sngrep, ngrep pcap tcpdump/wireshark   Please rate this rating

cross compile native libwebrtc ( on x86_64 host) for arm64 No ratings yet.

Direct compile webrtc on arm64 will fail: webrtc seems does not support direct support on arm, we will get errors: … Running hooks: 18% ( 4/22) sysroot_arm64 ________ running ‘vpython src/build/linux/sysroot_scripts/ –arch=arm64’ in ‘/webrtcbuilds/out’ Installing Debian sid arm64 root image: /webrtcbuilds/out/src/build/linux/debian_sid_arm64-sysroot Downloading Running hooks: 50% (11/22) binutils ________ running ‘vpython src/third_party/binutils/’ in ‘/webrtcbuilds/out’ Host • Read More »

How to synchronize audio video stream (a/v sync) 4.5/5 (2)

How to a/v sync in IETF RFC? The RFC specified how to do a/v sycn generally in RTP flows are synchronised by receivers based on information that is contained in RTCP SR packets generated by senders (specifically, the NTP-format timestamp and the RTP timestamp). Synchronisation requires that a common reference clock MUST be used • Read More »

SIP Register and Kamailio AoR No ratings yet.

The RFC 3262 said: The To header field contains the address of record whose registration is to be created, queried, or modified. That means TO contains AoR, and it should be some sort of sip uri. Normally we will see display name part in front of the sip uri. So if we send sip • Read More »

FAX: Error Far end cannot receive at the size of image 5/5 (1)

Fax ( over VoIP) Error:  Error Far end cannot receive at the size of image Resolution (1): from When you scan from certain Scanners it flips the image horizontally open the image and make sure that to flip it back to letter size vertical. (2)  or use gs to convert  pdf to tiff as the • Read More »

SIP header : Privacy meaning No ratings yet.

SIP protocol always seems to be complicated than I thought/expected. one example : Sip header Privacy This header is like this: Privacy: value the value could be: header, session, user, none, and critical ( defined in RFC 3323) id ( defined in RFC 3325 ) history ( defined RFC 4244 ) The basic idea seems to be • Read More »

WebRTC janus gateway use cases No ratings yet.

If you are  interested in the webrtc, this project is quite interesting great demo at: the source code is at: I did contribute two commits a year ago Time flies!   I feel this project could be used somewhere with some good use cases. If you have some interesting ideas on how to • Read More »

Asterisk real time db and rtcachefriends 5/5 (1)

I tried to use asterisk real time db, and somehow sip show peers does not show anything, After couple of hours googleing , and found this: rtcachefriends (global) If is turned on, Asterisk will cache friends that come from the realtime engine, just as if they had come from . This often helps with items such • Read More »