From owner-freebsd-questions Tue Jul 25 11:20:30 1995 Return-Path: questions-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.11/8.6.6) id LAA05387 for questions-outgoing; Tue, 25 Jul 1995 11:20:30 -0700 Received: from relay.hp.com (relay.hp.com [15.255.152.2]) by freefall.cdrom.com (8.6.11/8.6.6) with ESMTP id LAA05381 for ; Tue, 25 Jul 1995 11:20:29 -0700 Received: from hpmwtd.sr.hp.com by relay.hp.com with SMTP (1.37.109.16/15.5+ECS 3.3) id AA063296428; Tue, 25 Jul 1995 11:20:28 -0700 Received: from hpnmhjw.sr.hp.com by hpmwtd.sr.hp.com with SMTP (15.11.1.6/15.5+ECS 3.3) id AA04897; Tue, 25 Jul 95 11:20:27 -0700 Received: from mina.sr.hp.com by hpnmhjw.sr.hp.com with SMTP (1.37.109.16/15.5+ECS 3.3) id AA003476425; Tue, 25 Jul 1995 11:20:25 -0700 Message-Id: <199507251820.AA003476425@hpnmhjw.sr.hp.com> To: Ron Steele Cc: question freebsd Subject: Re: ping times using ppp In-Reply-To: Your message of "Mon, 24 Jul 1995 20:47:16 -0000." Date: Tue, 25 Jul 1995 11:20:24 -0700 From: Darryl Okahata Sender: questions-owner@FreeBSD.org Precedence: bulk > When trying to do interactive work over a ppp link, I find the latency > time very annoying. Ping generally reports round trip times of about > a quarter second. I use hardware handshaking and v.34 modem on > 16550 compatable serial card. Currenty 2.0R, soon to be upgrading. > > Does this time seem about right? Any ideas on how to improve these times? As Mike said, this isn't unusual. With my PPI V.FC (not V.34) modems, I see ping times around 160-180ms. To do error correction and data compression, modems "packetize" data; basically, when sending data, the modem tries to gather a packet of data (256 bytes, I think) before sending. However, this doesn't work well with interactive use, and so there's a timeout; when the timeout occurs, the partial packet is sent. This timeout is the cause of the long latencies (and note that two timeouts probably occur with ping -- one for each direction). -- Darryl Okahata Internet: darrylo@sr.hp.com DISCLAIMER: this message is the author's personal opinion and does not constitute the support, opinion or policy of Hewlett-Packard or of the little green men that have been following him all day.