vim very slow over SSH connection

I have a non-stellar SSH connection to some machine; the echo time is... I don't know, 0.2 seconds or so. Anyway, when I start vim, say with no input file, I experience a long delay, of about 3 to 4 seconds, which - when I connect over a lower-latency SSH connection (i.e. within the same network segment), I don't experience. This delay is _before_ vim has written anything to the terminal, and hence before it can expect me to input anything - so I'm wondering what's causing it to try to communicate over the connection, and what exactly it's communicating. I used strace -rr, looking for differences of over 0.1 seconds, and noticed a bunch of these lines:

0.284973 recvfrom(3, "\1\0\v\0\0\0\340\1", 8, 0, NULL, NULL) = 8
     0.133300 recvmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\1\0\1\0\0\0\0\0\1\205\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", iov_len=4096}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 32
     0.138255 recvmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\1\0\2\0\0\0\0\0\377\377?\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", iov_len=4096}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 32
     0.148123 recvmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\1\10\4\0M\1\0\0\37\0\0\0\0\0\0\0001\5\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., iov_len=4096}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 1364

(and this repeats itself again and again.) What's going on with these messages? And - how can I make vim skip these communications attempts and just come up faster?