A tour through brand new features for running rtpengine on network edges and customer premises for load testing.

1. rtpengine & kamailio
or how to simulate calls at scale
Andreas Granig <agranig@sipfront.com>

2. AT THE NETWORK EDGE
rtpengine & kamailio
Load Testing
Architecture
RTP Sinkhole NAT Piercing RTP Echo RTP PubSub

3. LOAD TESTING
ARCHITECTURE
rtpengine & kamailio
● Context
○ At sipfront.com, we develop a
SaaS for Telco Test Automation
● Load testing is resource intensive
○ sipp for signaling
○ tcpreplay for media
● kamailio & rtpengine to the rescue
○ protocol conversion for signaling
○ reflection & termination for media

4. LOAD TESTING ARCHITECTURE
rtpengine & kamailio
tcpreplay
+ RTP patch 1
sipp
SIP
RTP
kamailio
rtpengine
sinkhole
kamailio sipp
rtpengine
pierce-nat + echo
system
under
test
SDP info ctrl ctrl
NAT NAT
1
https://github.com/agranig/tcpreplay/tree/agranig/sipfront-rtp-edit

5. RTP SINKHOLE
rtpengine & kamailio
● Sometimes, you just don’t wanna talk…
○ but want to keep track of stats
○ and want to avoid ICMP port
unreachable messages

6. RTP SINKHOLE
rtpengine & kamailio
rtpengine
kamailio
SIP
RTP
media-echo=sinkhole
RTCP
MQTT stats

7. route {
# ...
if (outwards) {
rtpengine_offer("
direction=internal direction=external
media-echo=sinkhole generate-RTCP
");
}
# ...
}
reply_route {
# ...
if (outwards) {
rtpengine_answer("
direction=internal direction=external
media-echo=sinkhole generate-RTCP
");
}
# ...
}
RTP SINKHOLE
rtpengine & kamailio
rtpengine
--interface=internal/192.168.0.100
--interface=external/192.168.0.100!1.2.3.4
--listen-ng=127.0.0.1:12221
Kamailio Config rtpengine

8. NAT PIERCING
rtpengine & kamailio
● “you start first” - “no, you start first”
○ If you’d like to echo media
○ but the peer can’t send you anything
to echo back

9. NAT PIERCING
rtpengine & kamailio
kamailio
SIP
RTP
pierce-NAT
rtpengine
dummy RTP
NAT

10. route {
# ...
if (inwards) {
rtpengine_offer("
direction=external direction=internal
pierce-NAT
");
}
# ...
}
reply_route {
# ...
if (outwards) {
rtpengine_answer("
direction=external direction=internal
pierce-NAT
");
}
# ...
}
NAT PIERCING
rtpengine & kamailio
rtpengine
--interface=internal/192.168.0.100
--interface=external/192.168.0.100!1.2.3.4
--listen-ng=127.0.0.1:12221
Kamailio Config rtpengine

11. RTP ECHO
rtpengine & kamailio
● “You made this? I made this!”
○ send back incoming media with
new SSRC
○ for when you need two-way media
without the generation overhead

12. RTP ECHO
rtpengine & kamailio
kamailio
SIP
RTP
media-echo=forward | backward
rtpengine
RTP echo

13. route {
# ...
if (outwards) {
rtpengine_offer("
direction=internal direction=external
media-echo=backward
");
}
# ...
}
reply_route {
# ...
if (outwards) {
rtpengine_answer("
direction=internal direction=external
media-echo=forward
");
}
# ...
}
RTP ECHO
rtpengine & kamailio
rtpengine
--interface=internal/192.168.0.100
--interface=external/192.168.0.100!1.2.3.4
--listen-ng=127.0.0.1:12221
Kamailio Config rtpengine

14. RTP PUBSUB
rtpengine & kamailio
● “Listen up, everybody…”
○ Send an RTP stream once
○ and duplicate it to multiple
recipients
○ for SFU, SIPREC, Interception, …

15. RTP PUBSUB
rtpengine & kamailio
rtpengine
Kamailio
SIP - cid=X, ftag=A, ttag=B
RTP
offer
in: SDP
out: SDP
answer
in: SDP
out: SDP
subscribe-request
in: cid=X, ftag=A
out: SDP
SIP - cid=Y, ftag=C, ttag=D
subscribe-answer
in: cid=X, ftag=A, ttag=C, SDP
RTP
send-only
App Interceptor
publish
in: SDP
out: SDP
or optionally (if no SIP context):

16. RTP PUBSUB
rtpengine & kamailio
https://github.com/davehorton/rtpengine-client hopefully soon!
const Client = require('rtpengine-client').Client;
const client = new Client();
client
.subscribeRequest(12280, '127.0.0.1', {
'call-id': 'test-call-id',
'from-tag': 'test-tag'
})
.then((res) => {
console.log(`Received ${JSON.stringify(res)}`);
})
.catch((err) => {
console.log(`Error: ${err}`);
});
rtpengine
--interface=internal/192.168.0.100
--interface=external/192.168.0.100!1.2.3.4
--listen-ng=127.0.0.1:12221
--listen-http=127.0.0.1:12280
NodeJS rtpengine-client rtpengine

17. THANK YOU
Questions?
or any time online
Twitter: @andreasgranig
Email: agranig@sipfront.com
join private beta at
https://sipfront.com