Due to the lack of comments it is not clear, the topic is not interesting, either too simple or too complicated. I will describe what happened to me, maybe someone will come in handy. Instruction to create pjsip ipk + alsa. 1 Install OpenWRT Build System (in my case on Linux Mint 19.3) follow the manual. https://docs.onion.io/omega2-docs/cross-compiling.html Then. ol@ol-VirtualBox:~/OpenWRT-builds/onion_tst$ cd source/ $ ./scripts/feeds update -a $ ./scripts/feeds install -a $ make menuconfig Target System (MediaTek Ralink MIPS) Subtarget (MT76x8 based board) Target Profile (Multiple devices) [*] Target Devices/ (Onion Omega2+) Select telephony & alsa * Libraries/alsa-lib * Sound/alsa-utils * Libraries/Telephony/libpj * Libraries/Telephony/libpjlib-util * Libraries/Telephony/libpjmedia * Libraries/Telephony/libpjnath * Libraries/Telephony/libpjsip * Libraries/Telephony/libpjsip-simple * Libraries/Telephony/libpjsip-ua * Libraries/Telephony/libpjsua <*> Libraries/Telephony/libpjsua2 2 edit Makefile: <build-system>/source/feeds/telephony/libs/pjproject/Makefile // ln:38 add "+alsa-lib" DEPENDS:=$(CXX_DEPENDS) +libopenssl +libuuid +libpthread +alsa-lib // ln:65 change --disable-g711-codec // to --enable-g711-codec // ln:81 change --disable-sound // to --enable-sound If the first build (no toolchain) need run. $ make This make will create toolchain, image and ipk pakages. If there is a toolchain and you only need to create a pjsip packages, run. $ make package/feeds/telephony/pjproject/compile Result in. <build-system>/source/bin/packages/mipsel_24kc/telephony libpj_2.7.2-2_mipsel_24kc.ipk libpjlib-util_2.7.2-2_mipsel_24kc.ipk libpjsip_2.7.2-2_mipsel_24kc.ipk libpjnath_2.7.2-2_mipsel_24kc.ipk libpjmedia_2.7.2-2_mipsel_24kc.ipk libpjsip-simple_2.7.2-2_mipsel_24kc.ipk libpjsip-ua_2.7.2-2_mipsel_24kc.ipk libpjsua_2.7.2-2_mipsel_24kc.ipk libpjsua2_2.7.2-2_mipsel_24kc.ipk libsrtp2_2.1.0-1_mipsel_24kc.ipk My Omega2+: Ω-ware: 0.3.2 b239 Copy ipk files to Omega2 & install, in that order. root@Omega-A0E7:~/projects/ipk_my# opkg install libpj_2.7.2-2_mipsel_24kc.ipk root@Omega-A0E7:~/projects/ipk_my# opkg install libpjlib-util_2.7.2-2_mipsel_24kc.ipk root@Omega-A0E7:~/projects/ipk_my# opkg install libpjsip_2.7.2-2_mipsel_24kc.ipk root@Omega-A0E7:~/projects/ipk_my# opkg install libpjnath_2.7.2-2_mipsel_24kc.ipk root@Omega-A0E7:~/projects/ipk_my# opkg install libpjmedia_2.7.2-2_mipsel_24kc.ipk root@Omega-A0E7:~/projects/ipk_my# opkg install libpjsip-simple_2.7.2-2_mipsel_24kc.ipk root@Omega-A0E7:~/projects/ipk_my# opkg install libpjsip-ua_2.7.2-2_mipsel_24kc.ipk root@Omega-A0E7:~/projects/ipk_my# opkg install libpjsua_2.7.2-2_mipsel_24kc.ipk root@Omega-A0E7:~/projects/ipk_my# opkg install libpjsua2_2.7.2-2_mipsel_24kc.ipk root@Omega-A0E7:~/projects/ipk_my# opkg install libsrtp2_2.1.0-1_mipsel_24kc.ipk Install alsa from repository or from ipk files. root@Omega-A0E7:~/# opkg update root@Omega-A0E7:~/# opkg install alsa-utils Testing. Link to application, config & ipk https://drive.google.com/drive/folders/1Zr51okC9FJEvxXGqvt_Dmsm4doboAgEL?usp=sharing <streamutil-win> folder include streamutil application for windows, copy this folder on windows computer, edit ip address of Omega2 cli-streamutil-Tx-Unicast.bat & run cli-streamutil-Tx-Unicast.bat I am used Ethernet extention. Config Ethernet port of Omega2. Set same subnet for win & omega. <streamutil-omega> folder include streamutil application for OpenWRT, on Omega2 copy files streamutil and sutil_rx_ucast.sh & run sutil_rx_ucast.sh. The folder also contains files for building the project. <ipk> folder include ipk files for pjsip building with alsa support. .config: my menuconfig file.