diff -Nur squid-2.5.STABLE5-20040302/src/cf.data.pre squid-2.5.STABLE5-20040302.new/src/cf.data.pre
--- squid-2.5.STABLE5-20040302/src/cf.data.pre	2004-02-10 23:01:21.000000000 +0200
+++ squid-2.5.STABLE5-20040302.new/src/cf.data.pre	2004-03-20 02:05:35.000000000 +0200
@@ -2311,6 +2311,25 @@
 	matching line.
 DOC_END
 
+NAME: zph_tos
+TYPE: int
+DEFAULT: 0
+LOC: Config.zph_tos
+DOC_START
+	Allows you to select a TOS/Diffserv value to mark local and peer
+	hits. Read above (tcp_outgoing_tos) for details/requirements about TOS.
+	Default: 0 (disabled).
+DOC_END
+
+NAME: zph_tos_peer
+COMMENT: on|off
+TYPE: onoff
+LOC: Config.onoff.zph_tos_peer
+DEFAULT: on
+DOC_START
+	Set this to off if you want only local hits to be marked.
+DOC_END
+
 NAME: tcp_outgoing_address
 TYPE: acl_address
 DEFAULT: none
diff -Nur squid-2.5.STABLE5-20040302/src/client_side.c squid-2.5.STABLE5-20040302.new/src/client_side.c
--- squid-2.5.STABLE5-20040302/src/client_side.c	2004-02-18 20:51:16.000000000 +0200
+++ squid-2.5.STABLE5-20040302.new/src/client_side.c	2004-03-20 02:40:21.000000000 +0200
@@ -1971,6 +1971,40 @@
 	return;
     }
     if (http->out.offset == 0) {
+	if (Config.zph_tos) {
+	    int need_change = 0;
+	    int hit = 0;
+	    int tos = Config.zph_tos;
+	    int tos_old = 0;
+	    int tos_len = sizeof(tos_old);
+
+	    if (isTcpHit(http->log_type) ||
+		(Config.onoff.zph_tos_peer &&
+		(http->request->hier.code == PARENT_HIT ||
+		http->request->hier.code == SIBLING_HIT))) {
+		hit = 1;
+	    }
+	    if (http->request->flags.proxy_keepalive) {
+		if (getsockopt(fd, IPPROTO_IP, IP_TOS, &tos_old, &tos_len) < 0) {
+		    debug(33, 1) ("ZPH: getsockopt(IP_TOS) on FD %d: %s\n", fd, xstrerror());
+		} else if (hit && tos_old != tos) {	/* HIT: 1-st request, or previous was MISS */
+		    need_change = 1;
+		} else if (!hit && tos_old) {		/* MISS: previous was HIT */
+		    tos = 0;
+		    need_change = 1;
+		}
+	    } else if (hit) {				/* no keepalive */
+		need_change = 1;
+	    }
+	    if (need_change) {
+		enter_suid();
+		if (setsockopt(fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
+		    debug(33, 1) ("ZPH: setsockopt(IP_TOS) on FD %d: %s\n", fd, xstrerror());
+		}
+		leave_suid();
+	    }
+	}
+
 	rep = clientBuildReply(http, buf, size);
 	if (rep) {
 	    aclCheck_t *ch;
diff -Nur squid-2.5.STABLE5-20040302/src/structs.h squid-2.5.STABLE5-20040302.new/src/structs.h
--- squid-2.5.STABLE5-20040302/src/structs.h	2004-02-04 19:42:28.000000000 +0200
+++ squid-2.5.STABLE5-20040302.new/src/structs.h	2004-03-18 00:55:07.000000000 +0200
@@ -594,6 +594,7 @@
 	int pipeline_prefetch;
 	int request_entities;
 	int detect_broken_server_pconns;
+	int zph_tos_peer;
     } onoff;
     acl *aclList;
     struct {
@@ -695,6 +696,7 @@
     char *store_dir_select_algorithm;
     int sleep_after_fork;	/* microseconds */
     external_acl *externalAclHelperList;
+    int zph_tos;
 };
 
 struct _SquidConfig2 {