Загрузка файла из сети с определенной позиции

HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(Info.Url);                
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
_responseStream = response.GetResponseStream();
byte[] buffer= new byte[BUFFER_SIZE];
            
_responseStream.Seek(BytesDownloaded, SeekOrigin.Begin);
 
fileStream.Seek(BytesDownloaded, SeekOrigin.Begin);
while (Info.State==DownloadState.DOWNLOADING) {
    try {
        int size = _responseStream.Read(buffer, 0, buffer.Length);
        if (size == 0) {
            Info.State = DownloadState.COMPLETED;
            break;
        }
        fileStream.Write(buffer, 0, size);
    } catch (Exception ) {
            Info.State = DownloadState.ERROR;
    }
               
}

_responseStream.Seek(BytesDownloaded, SeekOrigin.Begin);

request.Headers.Add(HttpRequestHeader.Range, string.Format("bytes={0}-", BytesDownloaded));