回铃音 meaning in English

audible ringing tone
crbt
rbt ringback tone
ring back tone
ringing back tone

The system is composed of a web tier building under the struts framework and a business tier building under the struts waf . the two tiers are used together to achieve the system function . after that , it introduces how to use unionplatform to develop the application system
然后结合个性化回铃音业务系统( crbt )的门户系统,详细探讨了如何使用unionplatform框架来开发易于维护和易扩展的企业web应用系统,并就如何在unionplatform框架的基础进行扩展,开发自己的应用项目等关键技术进行了深入的研究。