The development of video streaming services on wireless ad hoc networks is a challenge task as a consequence of different limitations such as bandwidth-constrained, variable capacity links and energy-constrained operation. Moreover, the dynamic topology of nodes causes frequent link failures and high error rates. We propose in this paper a performance evaluation of the scalable video streaming over mobile ad hoc networks. In particular, we focus on the rate-adaptive strategy for streaming scalable video (H.264/SVC). In order to provide QoS mechanisms in the routing process, a new routing protocol is introduced. This protocol estimates the available bandwidth value, which is sent to video source in order to adapt the bit rate during the video transmission. We also propose a simulation framework that supports evaluation studies for scalable video streaming. In the simulation experiments, SVC streams with combined scalability (quality and temporal scalability) were used. As quality scalability method, we used Medium Grain Scalability (MGS). The results reveal that the rate-adaptive method helps avoid or reduce the congestion in MANETs obtaining a better quality in the received videos.