fix(call): resolve T103 timeout in 1:1 audio calls#202
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Root cause diagnosed by @botnick in #198: the responder never considers its conn_req satisfied because linejs was missing the BEPI/MC media-channel handshake and had inconsistent channel IDs. Changes: 1. Channel ID consistency: for 1:1 calls, set localMediaChanId equal to srcChanId so the conn_rsp body mChanId and cc-header srcChanId match (the native app keeps them identical). 2. DATA channel SRTP: derive a recv SRTP context for the peer's DATA stream (pt=98) in 1:1 calls, not just group calls. Without this, inbound data-channel packets fail auth tag verification. 3. MC JOIN_REQ / CHANGE_REQ handlers: the peer drives a BEPI media handshake after answer (join_req, change_req) that linejs never answered. Added handlers that respond with join_rsp (0x3285), change_rsp (0x3286), and check_rpt (0x3287). 4. bepi_channel_open (0x1102): send the SC-layer channel-open message after join_rsp, matching the native app's post-answer sequence. 5. Refactored defaultOneToOneDataSessionPayload to share stream spec with the new MC response handlers.
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Summary
Fixes the T103 timeout (
CONN_REQ_FAIL.timeout, relCode=511) in 1:1 audio calls, where the responder tears down the call ~10s after answering.Root cause diagnosed by @botnick in #198 (with full native app wire captures + Frida instrumentation):
conn_rspbody advertisedmChanId=Xbut cc-header usedsrcChanId=Y. The native app keeps these identical. The responder couldn't correlate our MC messages with the conn handshake.join_req,change_req) that linejs never answered. Without responses, the peer never considers the connection established.pt=98) failed SRTP auth because linejs only derived DATA keying for group calls.Changes
localMediaChanId = srcChanIdfor 1:1 calls — conn_rsp body and cc-header now use the same channel ID#configureMediafor 1:1 callsJOIN_REQ→JOIN_RSP(0x3285) handlerCHANGE_REQ→CHANGE_RSP(0x3286) handlerCHECK_RPT(0x3287) sent after joinbepi_channel_open(0x1102) SC-layer message sent after join_rspdefaultOneToOneDataSessionPayloadto reuse shared stream specReplaces the closed #199 which took a wrong approach (UPD_RSP keepalive).
Ref: #198
Test plan
deno checkpassesdeno fmtpasses