AFAIK, JUNOS uses the Adspec field for maximum transmission unit (MTU) negotiation.
So when an LSP is created across a set of links with different MTU sizes, the ingress router does not know what the smallest MTU is on the LSP path. By default, the maximum packet size for the LSP is based on the MTU for the outgoing interface for the LSP on the ingress router. If this MTU is larger than the MTU of one of the intermediate links, traffic might be dropped, because MPLS packets cannot be fragmented. To prevent this type of packet loss in MPLS LSPs, you can configure MTU signaling in RSVP. Juniper supports the Integrated Services object for MTU signaling in RSVP. MTU signaling in RSVP is disabled by default. To configure maximum transmission unit (MTU) signaling in RSVP, you need to configure MPLS to allow IP packets to be fragmented before they are encapsulated in MPLS. You also need to configure MTU signaling in RSVP. To configure MTU signaling in RSVP, include the path-mtu statement: path-mtu { allow-fragmentation; rsvp { mtu-signaling; <<-- } } l...@ntarique# run show mpls lsp transit detail Transit LSP: 1 sessions 192.168.255.1 From: 192.168.255.7, LSPstate: Up, ActiveRoute: 1 ... truncated... FastReroute desired PATH rcvfrom: 192.168.245.46 (so-0/2/1.0) 42 pkts Adspec: received MTU 1500 sent MTU 1500 <<<--- Thanks & Regards, Tarique A. Nalkhande -----Original Message----- From: juniper-nsp-boun...@puck.nether.net [mailto:juniper-nsp-boun...@puck.nether.net] On Behalf Of Thiago Drechsel Sent: Friday, August 07, 2009 6:37 PM To: Juniper List Subject: [j-nsp] Command to modify ADSPEC object default on PATH messages. Hi list. Does anybody know what is the configuration needed to add "Guaranteed Service" parameters, on ADSPEC object (RSVP PATH messages)? By default, I see that JUNOS only sends "Default General Parameters" and "Controlled Load" within PATH.... Thank you! -- Thiago Drechsel _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp