RESTful Web Service Building Diary (II) ---System Design

Introduction

Now we have to design the basic structure of our service. Firstly we have to get a general idea of how these communication services work, and try to fit them into a common abstract model. Then we need to look at the system requirements and database access. Combina all these, we will get a general system architecture design.

Commnication Service Comparison: Plivo vs twilio

Plivo uses RESTful API. It has C# helper library to make it easier to interact with the API. It also has web/mobile SDKs which you can used to build app using their services in browsal or phone. Since we are only try to make outbound call, the helper library is all we need. Also, it requires token to access its service, and most importantly, XML to custmize the response. From my personal practice, you need to put these XML on a public web server where Plivo can access, that’s kind of annoying.

Twilio is very similar to Plivo as far as I can see, for outbound calls. It’s also a Restful API with helper libaries, needs token for authorize and a url points to the response. The difference is it has its own markup language called TwiML.

Both services support SMS and voice messages, and as for voice message, their processes are very simialr. The only wield thing is, Plivo is much cheaper than twilio. There is a comparison here, seems like twilio’s API is better?

System Requiments

Must provide abstaction from actual service (like Plivo and twillio)
Must support both sending text or sending voice instruction
Must have unit tests for service portion
Have admin GUI to manage:
- Support API token management for different app
- View audit of all requests, with filter for time range and by api token
- Landing page should be dashboard of SMS stats.
- Create admins for portal management
callback/ 2 factor authentication
audits purge afer 2 years.

System Design

Using XML to specify the api call format
Common interface called Service to which defines the common actions for all services (Plivo or twillio)
ServiceController deals with restful api calls from user
AdminController deals with resquests from admin
User models stores user infomation
Response models stores response informaiton
Front-end for admin
Database for user information, log and response

Conclusion