yum-builddepが私のrpmをインストールするための依存関係を提供しないのはなぜですか？

私のrpmパッケージを読み取ろうとしましたが、この依存関係エラーが発生します。

[root@localhost ~]# rpm -ivh /root/x86_64/asterisk-1.8.12.2-1.fc15.x86_64.rpm 
error: Failed dependencies:
        libc.so.6(GLIBC_2.14)(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libc.so.6(GLIBC_2.7)(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libc.so.6(GLIBC_2.8)(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libcap.so.2()(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libcrypto.so.10()(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libedit.so.0()(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libgsm.so.1()(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libpopt.so.0(LIBPOPT_0)(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libresample.so.1()(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libspeexdsp.so.1()(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libsrtp.so.0()(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libssl.so.10()(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libtinfo.so.5()(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libxml2.so.2(LIBXML2_2.4.30)(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        libxml2.so.2(LIBXML2_2.6.0)(64bit) is needed by asterisk-1.8.12.2-1.fc15.x86_64
        rpmlib(FileDigests) <= 4.6.0-1 is needed by asterisk-1.8.12.2-1.fc15.x86_64
        rpmlib(PayloadIsXz) <= 5.2-1 is needed by asterisk-1.8.12.2-1.fc15.x86_64

依存関係エラーを解決するために、次のコマンドを使用しました。

[root@localhost ~]# yum-builddep asterisk-1.8.12.2-1.fc15.src.rpm 
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirrors.hns.net.in
 * extras: mirrors.hns.net.in
 * updates: mirrors.hns.net.in
Checking for new repos for mirrors
autoconf-2.59-12.noarch
automake-1.9.6-2.3.el5.noarch
openssl-devel-0.9.8e-22.el5_8.4.x86_64
newt-devel-0.52.2-15.el5.x86_64
ncurses-devel-5.5-24.20060715.x86_64
libcap-devel-1.10-26.x86_64
gtk2-devel-2.10.4-21.el5_7.7.x86_64
Error: No Package found for libsrtp-devel

Fedora-15のVirtualBoxにインストールされているCentOS 5.6を使用しています。