@Override
	public Transfer createDefaultTransfer() throws TransferException {
		// 尝试建立Sipc-proxy连接
		Transfer transfer = null;
		String sipcProxy = this.fetionContext.getLocaleSetting().getNodeText(
				"/config/servers/sipc-proxy");
		String sipcSslProxy = this.fetionContext.getLocaleSetting().getNodeText(
				"/config/servers/sipc-ssl-proxy");

		if (sipcProxy == null)
			sipcProxy = FetionConfig.getString("server.sipc-proxy");
		if (sipcSslProxy == null)
			sipcSslProxy = FetionConfig.getString("server.sipc-ssl-proxy");

		transfer = this.tryCreateTransfer(sipcProxy);
		// 尝试建立sipc-proxy-ssl连接
		if (transfer == null)
			transfer = this.tryCreateTransfer(sipcSslProxy);

		if (transfer == null) {
			// 仍然建立失败，抛出异常
			throw new TransferException("Couldn't create default transfer..");
		} else {
			// 建立成功
			this.localport = this.getLocalPort(transfer);
			return transfer;
		}
	}