when far end answers with only pcma, passthrough instead of transcoding to pcmu (#208)

* Update call-session.js

* Update call-session.js

.eslintignore

@@ -1 +0,0 @@
-test/*

.eslintrc.json

@@ -1,126 +0,0 @@
-{
-  "env": {
-    "node": true,
-    "es6": true  
-  },
-  "parserOptions": {
-    "ecmaFeatures": {
-      "jsx": false,
-      "modules": false
-    },
-    "ecmaVersion": 2020
-  },
-  "plugins": ["promise"],
-  "rules": {
-    "promise/always-return": "error",
-    "promise/no-return-wrap": "error",
-    "promise/param-names": "error",
-    "promise/catch-or-return": "error",
-    "promise/no-native": "off",
-    "promise/no-nesting": "warn",
-    "promise/no-promise-in-callback": "warn",
-    "promise/no-callback-in-promise": "warn",
-    "promise/no-return-in-finally": "warn",
-
-    // Possible Errors
-    // http://eslint.org/docs/rules/#possible-errors
-    "comma-dangle": [2, "only-multiline"],
-    "no-control-regex": 2,
-    "no-debugger": 2,
-    "no-dupe-args": 2,
-    "no-dupe-keys": 2,
-    "no-duplicate-case": 2,
-    "no-empty-character-class": 2,
-    "no-ex-assign": 2,
-    "no-extra-boolean-cast" : 2,
-    "no-extra-parens": [2, "functions"],
-    "no-extra-semi": 2,
-    "no-func-assign": 2,
-    "no-invalid-regexp": 2,
-    "no-irregular-whitespace": 2,
-    "no-negated-in-lhs": 2,
-    "no-obj-calls": 2,
-    "no-proto": 2,
-    "no-unexpected-multiline": 2,
-    "no-unreachable": 2,
-    "use-isnan": 2,
-    "valid-typeof": 2,
-
-    // Best Practices
-    // http://eslint.org/docs/rules/#best-practices
-    "no-fallthrough": 2,
-    "no-octal": 2,
-    "no-redeclare": 2,
-    "no-self-assign": 2,
-    "no-unused-labels": 2,
-
-    // Strict Mode
-    // http://eslint.org/docs/rules/#strict-mode
-    "strict": [2, "never"],
-
-    // Variables
-    // http://eslint.org/docs/rules/#variables
-    "no-delete-var": 2,
-    "no-undef": 2,
-    "no-unused-vars": [2, {"args": "none"}],
-
-    // Node.js and CommonJS
-    // http://eslint.org/docs/rules/#nodejs-and-commonjs
-    "no-mixed-requires": 2,
-    "no-new-require": 2,
-    "no-path-concat": 2,
-    "no-restricted-modules": [2, "sys", "_linklist"],
-
-    // Stylistic Issues
-    // http://eslint.org/docs/rules/#stylistic-issues
-    "comma-spacing": 2,
-    "eol-last": 2,
-    "indent": [2, 2, {"SwitchCase": 1}],
-    "keyword-spacing": 2,
-    "max-len": [2, 120, 2],
-    "new-parens": 2,
-    "no-mixed-spaces-and-tabs": 2,
-    "no-multiple-empty-lines": [2, {"max": 2}],
-    "no-trailing-spaces": [2, {"skipBlankLines": false }],
-    "quotes": [2, "single", "avoid-escape"],
-    "semi": 2,
-    "space-before-blocks": [2, "always"],
-    "space-before-function-paren": [2, "never"],
-    "space-in-parens": [2, "never"],
-    "space-infix-ops": 2,
-    "space-unary-ops": 2,
-
-    // ECMAScript 6
-    // http://eslint.org/docs/rules/#ecmascript-6
-    "arrow-parens": [2, "always"],
-    "arrow-spacing": [2, {"before": true, "after": true}],
-    "constructor-super": 2,
-    "no-class-assign": 2,
-    "no-confusing-arrow": 2,
-    "no-const-assign": 2,
-    "no-dupe-class-members": 2,
-    "no-new-symbol": 2,
-    "no-this-before-super": 2,
-    "prefer-const": 2
-  },
-  "globals": {
-    "DTRACE_HTTP_CLIENT_REQUEST"           : false,
-    "LTTNG_HTTP_CLIENT_REQUEST"            : false,
-    "COUNTER_HTTP_CLIENT_REQUEST"          : false,
-    "DTRACE_HTTP_CLIENT_RESPONSE"          : false,
-    "LTTNG_HTTP_CLIENT_RESPONSE"           : false,
-    "COUNTER_HTTP_CLIENT_RESPONSE"         : false,
-    "DTRACE_HTTP_SERVER_REQUEST"           : false,
-    "LTTNG_HTTP_SERVER_REQUEST"            : false,
-    "COUNTER_HTTP_SERVER_REQUEST"          : false,
-    "DTRACE_HTTP_SERVER_RESPONSE"          : false,
-    "LTTNG_HTTP_SERVER_RESPONSE"           : false,
-    "COUNTER_HTTP_SERVER_RESPONSE"         : false,
-    "DTRACE_NET_STREAM_END"                : false,
-    "LTTNG_NET_STREAM_END"                 : false,
-    "COUNTER_NET_SERVER_CONNECTION_CLOSE"  : false,
-    "DTRACE_NET_SERVER_CONNECTION"         : false,
-    "LTTNG_NET_SERVER_CONNECTION"          : false,
-    "COUNTER_NET_SERVER_CONNECTION"        : false  
-  }
-}

.gitignore

@@ -36,3 +36,4 @@ node_modules
 .DS_Store
 
 examples/*
+CLAUDE.md

Dockerfile

@@ -1,10 +1,10 @@
-FROM --platform=linux/amd64 node:18.15-alpine3.16 as base
+FROM --platform=linux/amd64 node:24-alpine AS base
 
 RUN apk --update --no-cache add --virtual .builds-deps build-base python3
 
 WORKDIR /opt/app/
 
-FROM base as build
+FROM base AS build
 
 COPY package.json package-lock.json ./
 
@@ -18,6 +18,6 @@ COPY --from=build /opt/app /opt/app/
 
 ARG NODE_ENV
 
-ENV NODE_ENV $NODE_ENV
+ENV NODE_ENV=$NODE_ENV
 
 CMD [ "node", "app.js" ]

eslint.config.js

@@ -0,0 +1,137 @@
+const promisePlugin = require('eslint-plugin-promise');
+
+module.exports = [
+  {
+    ignores: ['test/*']
+  },
+  {
+    files: ['**/*.js'],
+    languageOptions: {
+      ecmaVersion: 2020,
+      sourceType: 'commonjs',
+      globals: {
+        // Node.js globals
+        console: 'readonly',
+        process: 'readonly',
+        Buffer: 'readonly',
+        __dirname: 'readonly',
+        __filename: 'readonly',
+        module: 'readonly',
+        require: 'readonly',
+        exports: 'readonly',
+        setTimeout: 'readonly',
+        clearTimeout: 'readonly',
+        setInterval: 'readonly',
+        clearInterval: 'readonly',
+        setImmediate: 'readonly',
+        clearImmediate: 'readonly',
+        // DTrace/LTTNG globals
+        DTRACE_HTTP_CLIENT_REQUEST: false,
+        LTTNG_HTTP_CLIENT_REQUEST: false,
+        COUNTER_HTTP_CLIENT_REQUEST: false,
+        DTRACE_HTTP_CLIENT_RESPONSE: false,
+        LTTNG_HTTP_CLIENT_RESPONSE: false,
+        COUNTER_HTTP_CLIENT_RESPONSE: false,
+        DTRACE_HTTP_SERVER_REQUEST: false,
+        LTTNG_HTTP_SERVER_REQUEST: false,
+        COUNTER_HTTP_SERVER_REQUEST: false,
+        DTRACE_HTTP_SERVER_RESPONSE: false,
+        LTTNG_HTTP_SERVER_RESPONSE: false,
+        COUNTER_HTTP_SERVER_RESPONSE: false,
+        DTRACE_NET_STREAM_END: false,
+        LTTNG_NET_STREAM_END: false,
+        COUNTER_NET_SERVER_CONNECTION_CLOSE: false,
+        DTRACE_NET_SERVER_CONNECTION: false,
+        LTTNG_NET_SERVER_CONNECTION: false,
+        COUNTER_NET_SERVER_CONNECTION: false
+      }
+    },
+    plugins: {
+      promise: promisePlugin
+    },
+    rules: {
+      // Promise plugin rules
+      'promise/always-return': 'error',
+      'promise/no-return-wrap': 'error',
+      'promise/param-names': 'error',
+      'promise/catch-or-return': 'error',
+      'promise/no-native': 'off',
+      'promise/no-nesting': 'warn',
+      'promise/no-promise-in-callback': 'warn',
+      'promise/no-callback-in-promise': 'warn',
+      'promise/no-return-in-finally': 'warn',
+
+      // Possible Errors
+      'comma-dangle': [2, 'only-multiline'],
+      'no-control-regex': 2,
+      'no-debugger': 2,
+      'no-dupe-args': 2,
+      'no-dupe-keys': 2,
+      'no-duplicate-case': 2,
+      'no-empty-character-class': 2,
+      'no-ex-assign': 2,
+      'no-extra-boolean-cast': 2,
+      'no-extra-parens': [2, 'functions'],
+      'no-extra-semi': 2,
+      'no-func-assign': 2,
+      'no-invalid-regexp': 2,
+      'no-irregular-whitespace': 2,
+      'no-obj-calls': 2,
+      'no-proto': 2,
+      'no-unexpected-multiline': 2,
+      'no-unreachable': 2,
+      'use-isnan': 2,
+      'valid-typeof': 2,
+
+      // Best Practices
+      'no-fallthrough': 2,
+      'no-octal': 2,
+      'no-redeclare': 2,
+      'no-self-assign': 2,
+      'no-unused-labels': 2,
+
+      // Strict Mode
+      'strict': [2, 'never'],
+
+      // Variables
+      'no-delete-var': 2,
+      'no-undef': 2,
+      'no-unused-vars': [2, {args: 'none'}],
+
+      // Node.js and CommonJS
+      'no-mixed-requires': 2,
+      'no-new-require': 2,
+      'no-path-concat': 2,
+
+      // Stylistic Issues
+      'comma-spacing': 2,
+      'eol-last': 2,
+      'indent': [2, 2, {SwitchCase: 1}],
+      'keyword-spacing': 2,
+      'max-len': [2, 120, 2],
+      'new-parens': 2,
+      'no-mixed-spaces-and-tabs': 2,
+      'no-multiple-empty-lines': [2, {max: 2}],
+      'no-trailing-spaces': [2, {skipBlankLines: false}],
+      'quotes': [2, 'single', 'avoid-escape'],
+      'semi': 2,
+      'space-before-blocks': [2, 'always'],
+      'space-before-function-paren': [2, 'never'],
+      'space-in-parens': [2, 'never'],
+      'space-infix-ops': 2,
+      'space-unary-ops': 2,
+
+      // ECMAScript 6
+      'arrow-parens': [2, 'always'],
+      'arrow-spacing': [2, {before: true, after: true}],
+      'constructor-super': 2,
+      'no-class-assign': 2,
+      'no-confusing-arrow': 2,
+      'no-const-assign': 2,
+      'no-dupe-class-members': 2,
+      'no-new-symbol': 2,
+      'no-this-before-super': 2,
+      'prefer-const': 2
+    }
+  }
+];

lib/call-session.js

@@ -9,7 +9,8 @@ const {
   makeFullMediaReleaseKey,
   makePartnerFullMediaReleaseKey,
   isValidDomainOrIP,
-  removeVideoSdp
+  removeVideoSdp,
+  determineAnswerCodec
 } = require('./utils');
 const { MediaPath } = require('./constants.json');
 const {forwardInDialogRequests} = require('drachtio-fn-b2b-sugar');
@@ -99,11 +100,12 @@ const updateRtpEngineFlags = (sdp, opts) => {
   try {
     const parsed = sdpTransform.parse(sdp);
     const codec = parsed.media[0].rtp[0].codec;
+    // Only add telephone-event support, don't restrict to specific G.711 codec yet
+    // This allows far end to choose between PCMU/PCMA freely
     if (['PCMU', 'PCMA'].includes(codec)) {
-      opts.flags.push(`codec-accept-${codec}`);
       opts.flags.push('codec-accept-telephone-event');
     }
-  } catch (err) {}
+  } catch {}
   return opts;
 };
 
@@ -554,12 +556,16 @@ class CallSession extends Emitter {
             localSdpB: response.sdp,
             localSdpA: async(sdp, res) => {
               this.rtpEngineOpts.uac.tag = res.getParsedHeader('To').params.tag;
+
+              // Determine which codec to use based on far end negotiation
+              const {codec} = determineAnswerCodec(sdp, this.req.body, this.logger);
+
               const opts = {
                 ...this.rtpEngineOpts.common,
                 ...this.rtpEngineOpts.uas.mediaOpts,
                 'from-tag': this.rtpEngineOpts.uas.tag,
                 'to-tag': this.rtpEngineOpts.uac.tag,
-                flags: ['single codec', 'inject DTMF'],
+                flags: ['single codec', 'inject DTMF', `codec-accept-${codec}`, 'codec-accept-telephone-event'],
                 sdp
               };
               const response = await this.answer(opts);
@@ -709,7 +715,7 @@ class CallSession extends Emitter {
             if (!IMMUTABLE_HEADERS.includes(h)) headers[h] = bye.headers[h];
           });
           await other.destroy({headers});
-        } catch (err) {}
+        } catch {}
 
         const trackingOn = process.env.JAMBONES_TRACK_ACCOUNT_CALLS ||
           process.env.JAMBONES_TRACK_SP_CALLS ||
@@ -1231,6 +1237,22 @@ Duration=${payload.duration} `
         this.activeCallIds.delete(this.req.get('Call-ID'));
         if (this.activeCallIds.size === 0) this.idleEmitter.emit('idle');
         uac.other.destroy();
+        if (this.req.locals.cdr) {
+          const now = Date.now();
+          const day = new Date();
+          const recordAllCalls = this.req.locals.record_all_calls;
+          let recording_url = `/Accounts/${this.account_sid}/RecentCalls/${this.req.locals.cdr.call_sid}/record`;
+          recording_url += `/${day.getFullYear()}/${(day.getMonth() + 1).toString().padStart(2, '0')}`;
+          recording_url += `/${day.getDate().toString().padStart(2, '0')}/${recordAllCalls}`;
+          this.writeCdrs({...this.req.locals.cdr,
+            terminated_at: now,
+            termination_reason: 'caller hungup',
+            sip_status: 200,
+            answered: true,
+            duration: Math.floor((now - this.req.locals.cdr.answered_at) / 1000),
+            ...(recordAllCalls && {recording_url})
+          }).catch((err) => this.logger.error({err}, 'Error writing cdr for completed call'));
+        }
         this.srf.endSession(this.req);
       });
 

lib/middleware.js

@@ -62,7 +62,7 @@ module.exports = (srf, logger, redisClient) => {
           });
           return req.srf.endSession(req);
         }
-      } catch (err) {
+      } catch {
         res.send(500);
         return req.srf.endSession(req);
       }

lib/utils.js

@@ -349,6 +349,55 @@ const removeVideoSdp = (sdp) => {
   parsedSdp.media = parsedSdp.media.filter((media) => media.type !== 'video');
   return sdpTransform.write(parsedSdp);
 };
+
+const determineAnswerCodec = (farEndSdp, featureServerSdp, logger) => {
+  try {
+    // Parse both SDPs
+    const farEndParsed = sdpTransform.parse(farEndSdp);
+    const fsParsed = sdpTransform.parse(featureServerSdp);
+
+    // Get negotiated codec from far end (first codec in answer)
+    const negotiatedCodec = farEndParsed.media[0].rtp[0].codec;
+
+    // Get all codecs offered by feature server
+    const fsCodecs = fsParsed.media[0].rtp.map((r) => r.codec);
+
+    logger.debug({negotiatedCodec, fsCodecs}, 'determineAnswerCodec: analyzing codec negotiation');
+
+    // If far end negotiated G.711 (PCMU/PCMA) AND it was in the FS offer, pass it through
+    if (['PCMU', 'PCMA'].includes(negotiatedCodec) && fsCodecs.includes(negotiatedCodec)) {
+      logger.info({negotiatedCodec}, 'G.711 codec passthrough - no transcoding needed');
+      return {
+        codec: negotiatedCodec,
+        needsTranscoding: false
+      };
+    }
+
+    // Otherwise, we need to transcode to first G.711 codec in FS offer
+    const firstG711 = fsCodecs.find((c) => ['PCMU', 'PCMA'].includes(c));
+    if (firstG711) {
+      logger.info({negotiatedCodec, transcodeTarget: firstG711}, 'Transcoding required to G.711');
+      return {
+        codec: firstG711,
+        needsTranscoding: true
+      };
+    }
+
+    // Fallback: use PCMU
+    logger.info({negotiatedCodec}, 'No G.711 in FS offer, defaulting to PCMU');
+    return {
+      codec: 'PCMU',
+      needsTranscoding: true
+    };
+  } catch (err) {
+    logger.error({err}, 'Error determining answer codec, defaulting to PCMU');
+    return {
+      codec: 'PCMU',
+      needsTranscoding: true
+    };
+  }
+};
+
 module.exports = {
   makeRtpEngineOpts,
   selectHostPort,
@@ -364,5 +413,6 @@ module.exports = {
   makeFullMediaReleaseKey,
   makePartnerFullMediaReleaseKey,
   isValidDomainOrIP,
-  removeVideoSdp
+  removeVideoSdp,
+  determineAnswerCodec
 };

package.json

@@ -28,7 +28,7 @@
   },
   "dependencies": {
     "@babel/helpers": "^7.26.10",
-    "@jambonz/db-helpers": "^0.9.12",
+    "@jambonz/db-helpers": "^0.9.18",
     "@jambonz/http-health-check": "^0.0.1",
     "@jambonz/mw-registrar": "0.2.7",
     "@jambonz/realtimedb-helpers": "^0.8.13",
@@ -37,17 +37,17 @@
     "@jambonz/stats-collector": "^0.1.10",
     "@jambonz/time-series": "^0.2.10",
     "cidr-matcher": "^2.1.1",
-    "debug": "^4.3.4",
+    "debug": "^4.4.3",
     "drachtio-fn-b2b-sugar": "^0.2.1",
     "drachtio-srf": "^5.0.12",
-    "express": "^4.19.2",
-    "pino": "^8.20.0",
+    "express": "^4.21.2",
+    "pino": "^10.1.0",
     "sdp-transform": "^2.15.0"
   },
   "devDependencies": {
     "bent": "^7.3.12",
-    "eslint": "^7.32.0",
-    "eslint-plugin-promise": "^6.1.1",
+    "eslint": "^9.17.0",
+    "eslint-plugin-promise": "^7.2.1",
     "nyc": "^15.1.0",
     "tape": "^5.7.5"
   }