如何解决Broken pipe的错误.

如何解决Broken pipe的错误.
my $ssh = Net::SSH::Perl->new($host, cipher => '3des-cbc', debug => 'true', protocol => '2,1', port => 333);
$ssh->login("$username","$password");


执行上面的代码, 有时会出现一个错误如下 (Broken pipe). 不知道原因. 谢谢

pqaforum: Reading configuration data /home/watson/.ssh/config

pqaforum: Reading configuration data /etc/ssh_config

pqaforum: Connecting to espqaweb3.webex.com, port 333.

pqaforum: Remote version string: SSH-2.0-OpenSSH_3.9p1



pqaforum: Remote protocol version 2.0, remote software version OpenSSH_3.9p1

pqaforum: Net::SSH::Perl Version 1.30, protocol version 2.0.

pqaforum: No compat match: OpenSSH_3.9p1.

pqaforum: Connection established.

pqaforum: Sent key-exchange init (KEXINIT), wait response.

pqaforum: Algorithms, c->s: 3des-cbc hmac-sha1 none

pqaforum: Algorithms, s->c: 3des-cbc hmac-sha1 none

pqaforum: Entering Diffie-Hellman Group 1 key exchange.

pqaforum: Sent DH public key, waiting for reply.

pqaforum: Received host key, type 'ssh-dss'.

pqaforum: Host 'espqaweb3.webex.com' is known and matches the host key.

pqaforum: Computing shared secret key.

pqaforum: Verifying server signature.

pqaforum: Waiting for NEWKEYS message.

pqaforum: Enabling incoming encryption/MAC/compression.

pqaforum: Send NEWKEYS, enable outgoing encryption/MAC/compression.

pqaforum: Sending request for user-authentication service.

Broken pipe