Another disadvantage for sra algorithm is that it cannot avoid the instance that some traffic classes may be jammed abruptly , but other traffic classes have free resources . the thesis presents an algorithm , called peb _ esra ( pre - estimation and borrow based esra algorithm ) , which permits borrowing resources among traffic classes . to some extent , it solves the short - term unbalance of resources allocation 针对sra算法无法解决可能出现的某业务类突发性拥塞，而其他业务类尚有空闲资源的情况，论文在继承peesra算法的基础上，提出允许业务类之间资源借用的pebesra ( pre - estimationandborrowbasedesraalgorithm )算法，该算法在一定程度上缓解了由于业务流突发性拥塞造成的资源配置短期失衡问题。
