OpenSIPS - an event-driven SIP routing engine Liviu Chircu - 4th - - PowerPoint PPT Presentation

Liviu Chircu

• 4th Feb 2017 -

OpenSIPS - an event-driven SIP routing engine

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Outline

• Architecture timeline
• Event subscribe-notify
• Usage scenarios
• OpenSIPS scripts
• Conclusions

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Architecture timeline

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Step 1: “Linear” architecture

OpenSIPS 1.X

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Time SIP packet arrivals T h r e a d 1 T h r e a d 2 CPU bound I/O bound

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Step 2: “Async” architecture

OpenSIPS 2.1, 2.2

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Time SIP packet arrivals T h r e a d 1 CPU bound I/O bound

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Limitation: Processing is still linear!

Advanced SIP scenarios:

• Push Notifications
• FreeSWITCH ESL Events (e.g. DTMF)
• Call Pick-up

What’s missing:

• Communication & data exchange between different

processing contexts

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• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Step 3: “Event-driven” architecture

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Time SIP packet arrivals T h r e a d 1 T h r e a d 2

SIP msg A SIP msg B

wait(event X) resume() event X

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Step 3: “Event-driven” architecture

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Time SIP packet arrival T h r e a d 1

SIP msg A 4xx SIP reply

wait(event X) resume()

timeout!

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Step 3: “Event-driven” architecture

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Time SIP packet arrivals T h r e a d 1 T h r e a d 2

SIP msg A SIP msg B

trigger(handler, eventX) eventX handler

Event subscribe/notify

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Event Definition

• Triggered by actions / data processing during runtime
• Events hold key/value attributes
• OpenSIPS has a list of predefined events

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• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Subscribe

• interested OpenSIPS workers subscribe to events
• event subscriptions may contain filtering attributes

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• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Notify

• Notification == event
• Events are generated during runtime
• They are dispatched to all relevant subscribers
• Events are parametrized (e.g. DTMF digit, REG Contact)

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Usage scenarios

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Push Notifications

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INVITE bob 1xx PN REGISTER INVITE bob

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Push Notifications

Current way

• 1. incoming call for “bob”
• 2. send PN to “bob”’s mobile device
• 3. async sleep (N)
• 4. call(“bob”) if registered(“bob”) else goto 3.

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• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Push Notifications

Current way (limitations)

• 1. performance killer
• 2. inflexible, cannot handle complex scenarios
• parallel forking (desk + mobile devices)
• multiple gateways

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• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Push Notifications

In 2.3:

• 1. incoming call for “bob”
• 2. subscribe(“REGISTER”, “aor=bob”, “reg_handler”)
• 3. send PN to “bob”’s mobile device
• 4. fork calls to existing registrations

...

route [reg_handler] { fork_call(“$event(contact)”); }

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• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

DTMF-based fax/voicemail detection

In 2.3:

• 1. incoming call for “bob”
• 2. subscribe(“DTMF”, “callid=$ci”, “dtmf_handler”)
• 3. send call to “bob”

... route [dtmf_handler] { hangup() if $event(digit) != 2 }

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OpenSIPS Script

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Push Notifications

subscribe("REGISTER", "aor=bob", "reg_handler"); route(SEND_APN); if (lookup("location")) t_relay(); halt();

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• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Push Notifications

route [SEND_APN] { rest_append_hf("Authorization: key=CONSOLE_API_KEY"); rest_append_hf("Content-Type: \"application/json\""); rest_post("https://android.googleapis.com/gcm/send", "{ \"data\" : {\"foo\": \"bar\"}, \"registration_ids\":[\"REGISTRATION_ID\"] }"...); }

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• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Push Notifications

route [reg_handler] { route(CHECK_IF_MOBILE, "$event(contact)"); t_relay(); }

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Conclusions

• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

Conclusions

Event-driven approach:

• powerful & easy to use
• complex scenarios with simple script
• lightning fast!

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• FOSDEM ‘17 -

Liviu Chircu - OpenSIPS Project

OpenSIPS 2.3 - “integration”

• SIP capturing - Homer/SIPCapture
• billing - CGRateS
• software PBX - FreeSWITCH
• middleware - RabbitMQ

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• Liviu Chircu

○ OpenSIPS Project: www.opensips.org ○ liviu@opensips.org

Take-Away Message Under development!