refactor

- remove Redis
- handle proxing of non-success response

app.js

@@ -155,17 +155,6 @@ srf.locals = {
 };
 const activeCallIds = srf.locals.activeCallIds;
 
-/* report our call count to redis so a draining process can count calls across
-   all sbc-inbound and sbc-outbound processes on this server */
-if (!process.env.K8S && 'test' !== process.env.NODE_ENV) {
-  srf.locals.callCountReporter = require('./lib/call-count-reporter')({
-    logger,
-    addKey,
-    addToSet,
-    getCount: () => activeCallIds.size
-  });
-}
-
 const {
   initLocals,
   handleSipRec,
@@ -281,7 +270,7 @@ srf.invite((req, res) => {
   session.connect();
 });
 
-srf.use((err, req, res, next) => {
+srf.use((req, res, next, err) => {
   logger.error(err, 'hit top-level error handler');
   res.send(500);
 });

data/srtp-transcoding.json

@@ -4,7 +4,7 @@
     "ICE": "default",
     "SDES": "off",
     "flags": ["generate mid", "SDES-no", "port latching"],
-    "rtcp-mux": ["offer"]
+    "rtcp-mux": ["require"]  
   },
   "teams": {
     "transport-protocol": "RTP/SAVP",

eslint.config.js

@@ -96,7 +96,7 @@ module.exports = [
       // Variables
       'no-delete-var': 2,
       'no-undef': 2,
-      'no-unused-vars': [2, {args: 'none', ignoreRestSiblings: true}],
+      'no-unused-vars': [2, {args: 'none'}],
 
       // Node.js and CommonJS
       'no-mixed-requires': 2,

lib/autoscale-manager.js

@@ -23,55 +23,23 @@ module.exports = (logger) => {
             const {srf} = require('..');
             const {activeCallIds, removeFromRedis} = srf.locals;
 
-            /* reject new INVITEs with 503 so senders fail over to another SBC */
-            srf.locals.dryUpCalls = true;
-
             /* remove our private IP from the set of active SBCs so rtp and fs know we are gone */
             removeFromRedis();
 
-            /* count calls in progress across all sbc-inbound and sbc-outbound
-               processes on this server, if they are reporting; otherwise
-               fall back to counting only our own */
-            const countServerCalls = async() => {
-              const reporter = srf.locals.callCountReporter;
-              if (!reporter) return activeCallIds.size;
-              const {retrieveSet, retrieveKey} = srf.locals.realtimeDbHelpers;
-              const keys = await retrieveSet(reporter.setName);
-              let count = 0;
-              for (const key of keys) {
-                count += parseInt(await retrieveKey(key), 10) || 0;
-              }
-              return Math.max(count, activeCallIds.size);
-            };
-
-            /* poll until calls have dried up, then complete the scale-in;
-               require two consecutive zero readings since reported counts
-               may be up to 15s stale */
-            let consecutiveZeroCounts = 0;
-            const timer = setInterval(async() => {
-              try {
-                const calls = await countServerCalls();
-                if (0 === calls) {
-                  if (++consecutiveZeroCounts >= 2) {
-                    clearInterval(timer);
-                    logger.info('scale-in complete now that calls have dried up');
-                    lifecycleEmitter.completeScaleIn();
-                  }
-                }
-                else {
-                  consecutiveZeroCounts = 0;
-                  logger.info(`${calls} calls in progress on this server; scale-in will complete when they are done`);
-                }
-              } catch (err) {
-                logger.error({err}, 'Error counting calls in progress during scale-in');
-              }
-            }, 20000);
+            /* if we have zero calls, we can complete the scale-in right now */
+            const calls = activeCallIds.size;
+            if (0 === calls) {
+              logger.info('scale-in can complete immediately as we have no calls in progress');
+              lifecycleEmitter.completeScaleIn();
+            }
+            else {
+              logger.info(`${calls} calls in progress; scale-in will complete when they are done`);
+            }
           })
           .on(LifeCycleEvents.StandbyEnter, () => {
             lifecycleEmitter.dryUpCalls = true;
             const {srf} = require('..');
             const {removeFromRedis} = srf.locals;
-            srf.locals.dryUpCalls = true;
             removeFromRedis();
 
             logger.info('AWS enter pending state notification: begin drying up calls');
@@ -80,7 +48,6 @@ module.exports = (logger) => {
             lifecycleEmitter.dryUpCalls = false;
             const {srf} = require('..');
             const {addToRedis} = srf.locals;
-            srf.locals.dryUpCalls = false;
             addToRedis();
 
             logger.info('AWS exit pending state notification: re-enable calls');

lib/call-count-reporter.js

@@ -1,31 +0,0 @@
-const os = require('os');
-
-/**
- * Periodically report this process's count of calls in progress to redis.
- * A server may host several sbc-inbound and sbc-outbound processes; when one
- * of them handles an autoscale drain it needs to know when the entire server
- * has no calls in progress, not just its own process.  Each process writes
- * its own count under a per-pid key (with a short expiry, so keys from dead
- * processes evaporate) and registers that key in a per-host set that the
- * draining process can enumerate.
- */
-const REPORT_INTERVAL = 15000;
-const KEY_EXPIRY_SECS = 120;
-
-module.exports = ({logger, addKey, addToSet, getCount}) => {
-  const prefix = process.env.JAMBONES_CLUSTER_ID || 'default';
-  const setName = `${prefix}:call-count-keys:${os.hostname()}`;
-  const key = `${prefix}:call-count:${os.hostname()}:${process.pid}`;
-
-  const report = () => {
-    addKey(key, `${getCount()}`, KEY_EXPIRY_SECS)
-      .catch((err) => logger.error({err}, 'call-count-reporter: error writing call count'));
-  };
-
-  addToSet(setName, key)
-    .catch((err) => logger.error({err}, `call-count-reporter: error adding ${key} to ${setName}`));
-  setInterval(report, REPORT_INTERVAL);
-  report();
-
-  return {key, setName};
-};

lib/call-session.js

@@ -19,6 +19,9 @@ const debug = require('debug')('jambonz:sbc-inbound');
 const MS_TEAMS_USER_AGENT = 'Microsoft.PSTNHub.SIPProxy';
 const MS_TEAMS_SIP_ENDPOINT = 'sip.pstnhub.microsoft.com';
 const IMMUTABLE_HEADERS = ['via', 'from', 'to', 'call-id', 'cseq', 'max-forwards', 'content-length'];
+const NONCOPYABLE_RESPONSE_HEADERS = [
+  'via', 'from', 'to', 'call-id', 'cseq', 'contact', 'content-length', 'content-type'
+];
 
 /**
  * this is to make sure the outgoing From has the number in the incoming From
@@ -109,11 +112,7 @@ class CallSession extends Emitter {
 
   async connect() {
     const {sdp} = this.req.locals;
-    // use the parsed SDP from middleware (req.locals.sdp), not req.body:
-    // for multipart (SIPREC) or IWF-originated bodies req.body may be empty
-    // or not represent the actual offer, which would wrongly send an
-    // SDP-bearing call down the no-offer 3pcc path.
-    const is3pcc = !sdp || sdp.length === 0;
+    const is3pcc = this.req.body?.length === 0;
     this.logger.info(`inbound ${is3pcc ? '3pcc ' : ''}call accepted for routing`);
     const engine = this.getRtpEngine();
     if (!engine) {
@@ -285,6 +284,7 @@ class CallSession extends Emitter {
         proxy,
         headers,
         responseHeaders,
+        passFailure: false,
         proxyRequestHeaders: [
           'all',
           '-Authorization',
@@ -358,6 +358,19 @@ class CallSession extends Emitter {
         const tags = ['accepted:no', `sipStatus:${err.status}`, `originator:${this.req.locals.originator}`];
         this.stats.increment('sbc.terminations', tags);
         this.logger.info(`call failed to connect to feature server with ${err.status}`);
+
+        /* capture trace_id and application_sid from the feature server's error response for the CDR. */
+        if (this.req.locals.cdr && err.res) {
+          const trace_id = err.res.get('X-Trace-ID');
+          if (trace_id) {
+            this.req.locals.cdr.trace_id = trace_id;
+          }
+          const application_sid = err.res.get('X-Application-Sid');
+          if (application_sid) {
+            this.req.locals.cdr.application_sid = application_sid;
+          }
+        }
+
         this.emit('failed');
       }
       else if (err.message !== 'call canceled') {
@@ -372,6 +385,22 @@ class CallSession extends Emitter {
           .catch((err) => this.logger.error(err, 'Error decrementing call counts'));
 
       }
+
+      /* manually proxy the failure response to UAS so that the trace_id/application_sid capture above runs before
+         res.end fires (which is what triggers the failure-CDR writer). */
+      if (err.message !== 'call canceled' && !this.res.finalResponseSent) {
+        if (err instanceof SipError && err.res) {
+          const headers = {};
+          Object.keys(err.res.headers || {}).forEach((h) => {
+            if (!NONCOPYABLE_RESPONSE_HEADERS.includes(h)) headers[h] = err.res.headers[h];
+          });
+          this.res.send(err.status, err.reason, {headers});
+        }
+        else {
+          this.res.send(err.status || 500, err.reason);
+        }
+      }
+
       this.srf.endSession(this.req);
     }
   }
@@ -1109,7 +1138,6 @@ Duration=${payload.duration} `
         this.rtpEngineResource.destroy();
         this.activeCallIds.delete(this.req.get('Call-ID'));
         uac.other.destroy();
-        this._stopRecording();
         this.srf.endSession(this.req);
       });
 

lib/middleware.js

@@ -34,15 +34,6 @@ module.exports = function(srf, logger) {
 
   const initLocals = (req, res, next) => {
     const callId = req.get('Call-ID');
-
-    /* if we are drying up calls prior to scale-in, reject new INVITEs so the
-       sender fails over to another SBC; allow INVITE with Replaces through
-       since it targets a call already in progress on this server */
-    if (srf.locals.dryUpCalls && !req.has('Replaces')) {
-      logger.info({callId}, 'rejecting INVITE with 503 as we are drying up calls before scale-in');
-      return res.send(503);
-    }
-
     req.locals = req.locals || {callId};
     req.locals.nudge = 0;
 
@@ -68,13 +59,15 @@ module.exports = function(srf, logger) {
 
     /* write cdr for non-success response here */
     res.once('end', ({status}) => {
-      if (req.locals.cdr && req.locals.cdr.account_sid && status > 200  && 401 !== status) {
-        const trunk = ['trunk', 'teams'].includes(req.locals.originator) ? req.locals.carrier : req.locals.originator;
+      if (req.locals.cdr && req.locals.cdr.account_sid && status > 200 && 401 !== status) {
+        const trunk = ['trunk', 'teams'].includes(req.locals.originator) ?
+          req.locals.carrier : req.locals.originator;
         writeCdrs({...req.locals.cdr,
           terminated_at: Date.now(),
-          termination_reason: status === 487 === status ? 'caller abandoned' : 'failed',
+          termination_reason: status === 487 ? 'caller abandoned' : 'failed',
           sip_status: status,
-          trunk
+          trunk,
+          ...(req.locals.application_sid && {application_sid: req.locals.application_sid})
         }).catch((err) => logger.error({err}, 'Error writing cdr for call failure'));
       }
     });
@@ -139,8 +132,7 @@ module.exports = function(srf, logger) {
           logger.info('identifyAccount: rejecting call from carrier because DID has not been provisioned');
           return res.send(404, 'Number Not Provisioned');
         }
-        const {register_password, ...gatewayForLog} = gateway;
-        logger.info({gateway: gatewayForLog}, 'identifyAccount: incoming call from gateway');
+        logger.info({gateway}, 'identifyAccount: incoming call from gateway');
         const appSidHeader = req.get('x-application-sid');
         if (appSidHeader && appSidHeader == application_sid) {
           logger.info({callId}, 'Loop Detected, x-application-sid header on incoming call matches applicationSid');

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "sbc-inbound",
-  "version": "0.9.11",
+  "version": "0.9.6",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "sbc-inbound",
-      "version": "0.9.11",
+      "version": "0.9.6",
       "license": "MIT",
       "dependencies": {
         "@aws-sdk/client-auto-scaling": "^3.549.0",
@@ -15,7 +15,7 @@
         "@jambonz/db-helpers": "^0.9.18",
         "@jambonz/digest-utils": "^0.0.9",
         "@jambonz/http-health-check": "^0.0.1",
-        "@jambonz/realtimedb-helpers": "^0.8.21",
+        "@jambonz/realtimedb-helpers": "^0.8.18",
         "@jambonz/rtpengine-utils": "^0.4.4",
         "@jambonz/siprec-client-utils": "^0.2.10",
         "@jambonz/stats-collector": "^0.1.10",
@@ -24,7 +24,7 @@
         "cidr-matcher": "^2.1.1",
         "debug": "^4.4.3",
         "drachtio-fn-b2b-sugar": "0.2.1",
-        "drachtio-srf": "^5.0.27",
+        "drachtio-srf": "^5.0.21",
         "express": "^4.21.2",
         "pino": "^10.1.0",
         "verify-aws-sns-signature": "^0.1.0",
@@ -1538,10 +1538,9 @@
       }
     },
     "node_modules/@jambonz/realtimedb-helpers": {
-      "version": "0.8.21",
-      "resolved": "https://registry.npmjs.org/@jambonz/realtimedb-helpers/-/realtimedb-helpers-0.8.21.tgz",
-      "integrity": "sha512-Zn/Zw14U0L1pB2RlN5i160FwWqphonhQ7p880OzsKOuvg+wmj6qIkxdLjDXo6TSxFPXDHD25s33zfGOT6ZIfsw==",
-      "license": "MIT",
+      "version": "0.8.18",
+      "resolved": "https://registry.npmjs.org/@jambonz/realtimedb-helpers/-/realtimedb-helpers-0.8.18.tgz",
+      "integrity": "sha512-PfQRsOy/uKSA0ymRAEmTQnLxc1BZVRQWc+5mClLX6oB6vgvM/6YGgiuv5GSu26OtuKMTtS+RAxlFeT05iH/2rg==",
       "dependencies": {
         "debug": "^4.3.4",
         "ioredis": "^5.3.2"
@@ -3089,9 +3088,9 @@
       "integrity": "sha512-bMtje8GWVTze+UG6WSGnlUfBaYCuFiApNXl/XxWc+X9uATZiZkV2jIqhf+Y4SY3nS8dZclJIVKd9qwoCa+i+Vw=="
     },
     "node_modules/drachtio-srf": {
-      "version": "5.0.27",
-      "resolved": "https://registry.npmjs.org/drachtio-srf/-/drachtio-srf-5.0.27.tgz",
-      "integrity": "sha512-UCNITDPJreCurG5reM2TSmWSbT52azPaNqoc42L4nljy0aVuDt0Am9ExpAy5RfsP8ioxSY2VdSJehr1ARRJL+Q==",
+      "version": "5.0.21",
+      "resolved": "https://registry.npmjs.org/drachtio-srf/-/drachtio-srf-5.0.21.tgz",
+      "integrity": "sha512-9hkQ7LURI1ceTMs49Nh2aosAd2v0565eD8Ccho5sSzXEHuq0DE3epjStlThq6LvIGVVAOXuSQGXFmlMWK92R3w==",
       "license": "MIT",
       "dependencies": {
         "debug": "^4.4.3",
@@ -3099,7 +3098,7 @@
         "node-noop": "^1.0.0",
         "only": "^0.0.2",
         "sdp-transform": "^2.15.0",
-        "short-uuid": "^6.0.3",
+        "short-uuid": "^5.2.0",
         "sip-methods": "^0.3.0",
         "sip-status": "^0.1.0",
         "utils-merge": "^1.0.1",
@@ -6111,15 +6110,29 @@
       }
     },
     "node_modules/short-uuid": {
-      "version": "6.0.3",
-      "resolved": "https://registry.npmjs.org/short-uuid/-/short-uuid-6.0.3.tgz",
-      "integrity": "sha512-UMZ3rYOoid307EqWsPTnoBUSOB51Fi28vUMPigUsSCmbaSvslyf/SlXZWOn4btj8tokhBTBkPFKVKKlIolEG1w==",
+      "version": "5.2.0",
+      "resolved": "https://registry.npmjs.org/short-uuid/-/short-uuid-5.2.0.tgz",
+      "integrity": "sha512-296/Nzi4DmANh93iYBwT4NoYRJuHnKEzefrkSagQbTH/A6NTaB68hSPDjm5IlbI5dx9FXdmtqPcj6N5H+CPm6w==",
       "license": "MIT",
       "dependencies": {
-        "any-base": "^1.1.0"
+        "any-base": "^1.1.0",
+        "uuid": "^9.0.1"
       },
       "engines": {
-        "node": ">=14.17.0"
+        "node": ">=14"
+      }
+    },
+    "node_modules/short-uuid/node_modules/uuid": {
+      "version": "9.0.1",
+      "resolved": "https://registry.npmjs.org/uuid/-/uuid-9.0.1.tgz",
+      "integrity": "sha512-b+1eJOlsR9K8HJpow9Ok3fiWOWSIcIzXodvv0rQjVoOVNpWMpxf1wZNpt4y9h10odCNrqnYp1OBzRktckBe3sA==",
+      "funding": [
+        "https://github.com/sponsors/broofa",
+        "https://github.com/sponsors/ctavan"
+      ],
+      "license": "MIT",
+      "bin": {
+        "uuid": "dist/bin/uuid"
       }
     },
     "node_modules/side-channel": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "sbc-inbound",
-  "version": "0.9.11",
+  "version": "0.9.6",
   "main": "app.js",
   "engines": {
     "node": ">= 20.0.0"
@@ -32,7 +32,7 @@
     "@jambonz/db-helpers": "^0.9.18",
     "@jambonz/digest-utils": "^0.0.9",
     "@jambonz/http-health-check": "^0.0.1",
-    "@jambonz/realtimedb-helpers": "^0.8.21",
+    "@jambonz/realtimedb-helpers": "^0.8.18",
     "@jambonz/rtpengine-utils": "^0.4.4",
     "@jambonz/siprec-client-utils": "^0.2.10",
     "@jambonz/stats-collector": "^0.1.10",
@@ -41,7 +41,7 @@
     "cidr-matcher": "^2.1.1",
     "debug": "^4.4.3",
     "drachtio-fn-b2b-sugar": "0.2.1",
-    "drachtio-srf": "^5.0.27",
+    "drachtio-srf": "^5.0.21",
     "express": "^4.21.2",
     "pino": "^10.1.0",
     "verify-aws-sns-signature": "^0.1.0",