-| ... | Test suite uses 2-node topology TG - DUT1 - TG with two links
-| ... | between nodes as well as 3-node topology TG - DUT1 - DUT2 - TG
-| ... | with one link between nodes. Test packets are sent from TG to DUT1.
-| ... | DUT1 encapsulate packet into GRE and send out from other interface.
-| ... | Traffic scripts check received MAC headers, IP headers and GRE headers.
+| ... | *[Top] Network Topologies:* TG=DUT1 2-node topology with two links
+| ... | between nodes; TG-DUT1-DUT2-TG 3-node circular topology with single
+| ... | links between nodes.
+| ... | *[Enc] Packet Encapsulations:* Eth-IPv4-GRE-IPv4-ICMPv4 on DUT1-DUT2,
+| ... | Eth-IPv4-ICMPv4 on TG-DUTn for routing over GRE tunnel; Eth-IPv4-ICMPv4
+| ... | on TG_if1-DUT, Eth-IPv4-GRE-IPv4-ICMPv4 on TG_if2_DUT for GREoIPv4
+| ... | encapsulation and decapsulation verification.
+| ... | *[Cfg] DUT configuration:* DUT1 and DUT2 are configured with IPv4 routing
+| ... | and static routes. GREoIPv4 tunnel is configured between DUT1 and DUT2.
+| ... | *[Ver] TG verification:* Test ICMPv4 (or ICMPv6) Echo Request packets are
+| ... | sent in both directions by TG on links to DUT1 and DUT2; GREoIPv4
+| ... | encapsulation and decapsulation are verified separately by TG; on
+| ... | receive TG verifies packets for correctness and their IPv4 (IPv6)
+| ... | src-addr, dst-addr and MAC addresses.
+| ... | *[Ref] Applicable standard specifications:* RFC2784.