What occurs at the point of this ssh hang?

[Neil Carlson]

Judging from the following 'ssh -vvv' output, what process might be
happening and causing the hang at the indicated point?

OpenSSH_6.4, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 51: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to git.code.sf.net [216.34.181.155] port 22.
debug1: Connection established.
debug3: Incorrect RSA1 identifier
debug3: Could not load "/***/.ssh/id_rsa" as a RSA1 public key
debug1: identity file /***/.ssh/id_rsa type 1
debug1: identity file /***/.ssh/id_rsa-cert type -1
debug3: Incorrect RSA1 identifier
debug3: Could not load "/***/.ssh/id_dsa" as a RSA1 public key
debug1: identity file /***/.ssh/id_dsa type 2
debug1: identity file /***/.ssh/id_dsa-cert type -1
...
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.4

------  ssh hangs at this point -----

debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH_5*
debug2: fd 3 setting O_NONBLOCK
...