Investigate 

```
  ssl_session_cache shared:SSL:10m;  # 10MB -> ~40,000 sessions.
  ssl_session_timeout 24h;           # 24 hours
  ssl_buffer_size 1400;              # 1400 bytes to fit in one MTU
```

[Source](https://github.com/igrigorik/istlsfastyet.com/blob/master/nginx/nginx.conf#L13-15)
