if invite is sent with a domain name in request uri then assume the intention is for it to go out that way

lib/call-session.js

@@ -7,6 +7,9 @@ const {SipError, stringifyUri, parseUri} = require('drachtio-srf');
 const debug = require('debug')('jambonz:sbc-outbound');
 
 const makeInviteInProgressKey = (callid) => `sbc-out-iip${callid}`;
+
+const isDotDecimal = (host) => /^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$/.test(host);
+
 /**
  * this is to make sure the outgoing From has the number in the incoming From
  * and not the incoming PAI
@@ -25,9 +28,11 @@ const createBLegFromHeader = (req, teams) => {
   }
   return `sip:${user}@${host}`;
 };
-const createBLegToHeader = (req, teams) => {
+const createBLegToHeader = (req, teams, retainHostName) => {
   const to = req.getParsedHeader('To');
-  const host = teams ? req.get('X-MS-Teams-Tenant-FQDN') : 'localhost';
+  let host = 'localhost';
+  if (teams) host = req.get('X-MS-Teams-Tenant-FQDN');
+  else if (retainHostName) host = to.host;
   const uri = parseUri(to.uri);
   if (uri && uri.user) return `sip:${uri.user}@${host}`;
   return `sip:anonymous@${host}`;
@@ -185,11 +190,18 @@ class CallSession extends Emitter {
     try {
       // determine where to send the call
       debug(`connecting call: ${JSON.stringify(this.req.locals)}`);
+
+      /**
+       * if we receive an INVITE with a host part that is not a dot-decimal ipv4
+       * default to retaining that in the INVITE we send
+       * */
+      const parsedIncomingUri = parseUri(this.req.uri);
+      const retainHostName = !isDotDecimal(parsedIncomingUri.host);
       let headers = {
         'From': createBLegFromHeader(this.req, teams),
         'Contact': createBLegFromHeader(this.req, teams),
-        'To': createBLegToHeader(this.req, teams),
+        'To': createBLegToHeader(this.req, teams), retainHostName,
-        Allow: 'INVITE, ACK, OPTIONS, CANCEL, BYE, NOTIFY, UPDATE, PRACK',
+        Allow: 'INVITE, ACK, OPTIONS, CANCEL, BYE, NOTIFY, UPDATE, PRACK, REFER, INFO',
         'X-Account-Sid': this.account_sid
       };
 
@@ -262,21 +274,28 @@ class CallSession extends Emitter {
           if (gws.length) {
             uris = [];
             gws.forEach((o) => {
+              let proxy;
               const calledNumber = this.req.calledNumber.startsWith('+') ?
                 this.req.calledNumber.slice(1) :
                 this.req.calledNumber;
               const prefix = vc.tech_prefix || '';
               const protocol =  o.protocol?.startsWith('tls') ? 'tls' : (o.protocol || 'udp');
-              const hostport = !o.port || 5060 === o.port ? o.ipv4 : `${o.ipv4}:${o.port}`;
+              const host = retainHostName ? parsedIncomingUri.host : o.ipv4;
+              const hostport = !o.port || 5060 === o.port ? host : `${host}:${o.port}`;
               const prependPlus = vc.e164_leading_plus && !this.req.calledNumber.startsWith('0') ? '+' : '';
               const transport = `transport=${protocol}`;
               const scheme = protocol === 'tls' ? 'sips' : 'sip';
               const u = `${scheme}:${prefix}${prependPlus}${calledNumber}@${hostport};${transport}`;
+              if (retainHostName) {
+                const hostport = !o.port || 5060 === o.port ? o.ipv4 : `${o.ipv4}:${o.port}`;
+                proxy = `${scheme}:${hostport};transport=${transport}`;
+              }
               const obj = {
                 name: vc.name,
                 diversion: vc.diversion,
                 hostport,
-                protocol: o.protocol
+                protocol: o.protocol,
+                ...(proxy && {proxy})
               };
               if (vc.register_username && vc.register_password) {
                 obj.auth = {
@@ -355,7 +374,6 @@ class CallSession extends Emitter {
         // INVITE request line and To header should be the same.
         hdrs = {...hdrs, 'To': uri};
         if (gw) {
-          this.logger.info({gw}, `sending INVITE to ${uri} via carrier ${gw.name}`);
           if (gw.diversion) {
             let div = gw.diversion;
             if (div.startsWith('+')) {
@@ -367,6 +385,8 @@ class CallSession extends Emitter {
               'Diversion': div
             };
           }
+          proxy = gw.proxy;
+          this.logger.info({gw}, `sending INVITE to ${uri}`);
         }
         else this.logger.info(`sending INVITE to ${uri} via proxy ${proxy})`);
         try {