2. Hosted VoIP Services using Erlang/OTP
VoIP meets the Cloud

3. Where is the Cloud Going
Hardware
Clustering
Commodity Hardware
Software
Abstraction of application layer from hardware infrastructure
Web Long Polling
24/7 services – always on, on demand
Shorten Product Cycles
“Easy” languages

4. Cloud coding – Tougher than expected
Geometrical Complexity
Concurrency management
State management
Latency tuning
httpd scaling
Updating code is a chore

5. Problems? What problems?
Deadlocks
Shared memory corruption
Unreliable code updates (at best)
Synchronous httpd requests
Debugging
Replication
(and I haven’t even started)

7. Erlang Overview Joe Armstrong Designed for
concurrency
distributed systems
error containment
fault tolerance
hot code loading
Ericsson switches – % uptime (31ms/yr)

8. Designed for Concurrency
Basic unit of concurrency is a process
Really light-weight (~300 bytes)
Not really a kernel process
No shared memory with other processes
No differentiation between Local and Remote messages
Polymorphism through pattern matching
Native multi-master database
Runtime environment

9. Erlang in the wild

10. Case Study - Aptela
Positioned to deliver unified “intelligent communications” (voice, data, video) to small and medium businesses.
Launched on-demand PBX Software in 2001, transforming to Voice as a Service in 2005.
SaaS delivery of integrated hosted applications and nationwide VoIP telephony infrastructure.
Dynamic, growing customer base of companies completing over 20 million transactions per month.

11. Why switch to Erlang/OTP?
Concurrency management
State management
Faster Developer Ramp-up
Easier code management & deployment
Capacity tailing
The roving bottleneck
Fault tolerance

13. And? Development gains – Product Mgrs like the devs
Exposing features versus developing features
Components scale near-linearly
Uptime is not a four-letter word
Significant performance gains!

14. Enabling Integration